However, alongside this, your brewing water should also remain at a stable temperature throughout the entire process. This is a concept known as thermal stability – an essential part of manual brewing.

While temperature-controlled kettles can certainly help to improve thermal stability, your brewer also has an effect on it.

To learn more about how to maintain a stable brew temperature, I spoke with two coffee professionals. Read on to learn more on why thermal stability is so important. 

You may also like our article on how your dripper material affects your pour over coffee.

What is thermal stability?

There are many variables to keep track of when brewing filter coffee. These include coffee to water ratio, total brew time, grind size, agitation, and more. Temperature, however, is one of the most important.

When coffee is brewed, a number of soluble volatile compounds that contribute to flavour – such as oils and acids – are extracted. However, as different compounds are extracted at different temperatures, ensuring that you keep your temperature stable throughout the brew is key. 

Hyunhwa is the Head Barista at Nothin Coffee in Seoul, South Korea.

“Thermal stability in manual brewing means more consistency in your extraction,” he tells me. “Consistency helps to reflect the coffee’s inherent flavours and lets you prepare the best-tasting coffee.”

Any significant temperature fluctuations (3°C in either direction is significant enough) can result in either too many or too few compounds being extracted. Either way, this can have a notable impact on flavour.

If brewing temperatures are too high, the water extracts more volatile compounds, as well as increasing the rate of extraction – thereby reducing the total brew time. 

This makes it harder for the brewer to control the extraction rate, and can result in overextracted coffee, which tastes bitter and hollow.

Lower brewing temperatures, meanwhile, prolong the extraction process as the water molecules have less kinetic energy, meaning that they move around less. If your water temperature is too low, you risk underextraction, which means your coffee will taste sour and astringent.

Moreover, if the coffee bed is extracted with brewing water which is not at a stable temperature (for example, if the temperature of water decreases over the course of the brew time), some of the coffee grounds may be extracted more than others. This leads to coffee which is both underextracted and overextracted at the same time.

Explaining thermal stability

While maintaining thermal stability during manual brewing might seem easy enough with the aid of equipment like a temperature-controlled kettle, it can actually be more difficult than you might think. 

This is often because of the shape and material of the brewer.

Hyunjun Kim is the co-founder of Nothin Coffee and main developer of the Steadfast filter coffee brewer.

“The wide opening at the top of a standard filter coffee brewer allows more heat to escape into the surrounding air, rather than retaining it in the slurry,” he explains. “Therefore, manual brewing is more prone to heat loss during extraction. 

“This means the material of your brewer greatly affects thermal stability,” he adds.

Different materials used to manufacture filter brewers have different thermal masses. Thermal mass is a measurement of how much heat a material needs to absorb before its temperature increases. 

Materials like concrete and stone, for instance, have a high thermal mass, because they need to absorb a lot of heat before their temperature rises. 

“A filter brewer with a higher thermal mass requires more energy from the brewing water, which it absorbs through heat,” Hyunjun says. “This means it takes longer to warm up.

“On the other hand, materials with a lower thermal mass require less energy to warm up, and they absorb heat out of the slurry much more quickly.”

Hyunhwa, meanwhile, emphasises the importance of using a dripper which is made from materials that will retain heat for longer. This is because brewers which lose heat quickly can disrupt the temperature of the water, and therefore affect extraction.

“Typically, steel conducts heat much faster, while plastics absorb and emit heat at a slower rate,” Hyunhwa tells me. “This means that, generally speaking, plastic filter drippers are more insulated than metal ones.

“However, specially-insulated metal brewers like Steadfast conduct and retain heat more effectively for the best possible thermal stability.”

Comparing different brewer materials

We know different materials have different thermal masses, and therefore we know that they conduct heat at different rates.

But how significant is the difference? And what else should you consider for thermal stability?

Plastics 

Hyunjun tells me that most plastic brewers are made from “a range of polymers, commonly methyl methacrylate, which is also commonly referred to as acrylic”.

Plastics have a high thermal mass (around three times that of steel), which means it takes longer for the material to absorb heat from the brewing water.

In fact, plastics emit heat around 20 times slower than other materials, which helps to maintain a stable brew temperature for longer periods. 

Ceramic and porcelain 

Hyunhwa says ceramic and porcelain are popular materials for manual brewers because of their “high insulating qualities and visual appeal”.

Ceramic has a slightly lower thermal mass than plastic, which also makes it a good material for ensuring thermal stability.

However, since ceramic is a dense material, it absorbs more heat than plastic, even at the same temperature ranges.

“Ceramic brewers absorb around four times more heat from your brewing water than plastic ones,” Hyunhwa explains. 

Glass

Glass is another popular material for manual brewers. 

Alongside its visual appeal, it also has a significantly lower specific thermal mass than plastic and ceramic brewers, so it needs less energy to reach the right temperatures for brewing. 

“Glass filter brewers also tend to weigh around half as much as most ceramic or porcelain ones,” Hyunhwa says. “This means they are more insulated when it comes to the water temperature.”

Steel

Steel has a very low thermal mass compared to other materials, so it can heat up much more quickly. This means it requires much less time and energy to reach the optimal brewing temperature. 

“However, because of the thinner materials, steel brewers can absorb more heat from the brew and release it into the atmosphere,” Hyunjun says. 

As a result of this, he recommends using steel drippers for recipes which have a total brew time of three minutes or less. 

However, Hyunjun also points out that using an insulated steel filter brewer, such as the one made by Steadfast, means taking less energy and time to reach the ideal temperature, as well as better heat retention over time.

“The Steadfast coffee brewer is made from high-quality stainless steel (SUS304) and comes with an outer insulated leather jacket, which helps to stabilise the brewing temperature,” Hyunjun tells me.

“This means it can reach the target temperature more quickly because of the steel’s lower thermal mass, while the insulated jacket improves thermal stability throughout the brew,” he adds.

Hyunhwa explains that Steadfast recently carried out a study to compare plastic and ceramic brewers to their dripper.

“Among the three brewers, the Steadfast reached the target temperature the fastest, and maintained the temperature for longer,” Hyunhwa says.

He adds that alongside the insulated leather jacket, Steadfast is also specifically designed to maintain thermal stability during manual brewing.

The dripper has a trapezoid wedge shape, with walls which slope at a 31° angle (similar to a conical brewer like the V60). This helps to not only maintain brew temperature, but also improves flow rate during extraction. 

Can you improve thermal stability?

Hyunhwa tells me that when filter coffee is brewed, heat loss generally occurs across the surface of the slurry, because of the wide opening at the top of the brewer.

“Because of this, we recommend preheating your brewer to avoid losing too much heat from your brew water,” he adds.

Denser materials like ceramic and plastic should be more thoroughly preheated than steel and glass, as they take longer to heat up. This prevents them from absorbing too much heat during the initial phases of extraction.

Ultimately, using high-quality brewers made from durable materials helps you to achieve a consistent, stable temperature when preparing filter coffee.

“With the Steadfast, we focused on convenience, durability, and making sure people enjoyed brewing coffee with the dripper,” Hyunjun says. “To achieve all of this, we used SUS304 – a food-grade stainless steel known for its durability – and a leather jacket made from plant-based natural tannins.”

Your dripper material undoubtedly has an impact on thermal stability and brew temperature, which in turns affects extraction and the flavours you taste in your cup.

When choosing a brewer, consider the materials you use and how they can affect thermal stability. By selecting a brewer with a lower thermal mass, or one that is insulated, you are more likely to maintain the required temperature of your brewing water.

This way, you can focus on the many other extraction variables that are important for preparing high-quality coffee.

Enjoyed this? Then read our article on how temperature can impact your experience of coffee.

Photo credits: Steadfast

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In order to ensure the coffee is evenly saturated with water, two of the most commonly used techniques are swirling and stirring the mixture, which is often referred to as the “slurry”. But which is best?

To learn more about these two brewing practices, I spoke to three coffee professionals from across the industry. Read on to find out what they said.

You might also like What’s The Difference Between Filter Coffee And Americano?

Why Should We Swirl Or Stir During Brewing?

Andrée Rios is an SCA certified barista living in Barcelona. He says that in order to achieve even extraction levels, you need to agitate the slurry.

“The main purpose of stirring and spinning is to improve the distribution of water among the grounds in the coffee bed,” he says. “This minimises channeling and dry particle resistance.

“Ideally, we should try to get our coffee grounds to contribute collectively and evenly from the first droplet of poured water until the last.”

A more even extraction will result in better tasting coffee. Under-extracted coffee is generally sour and overly acidic, while over-extracted coffee tastes bitter and dry.

The final appearance of the wet coffee grounds (known as “the bed”) can help the brewer assess their extraction.

“A properly distributed, homogeneous, and flat bed with little to no particles [high up the filter paper] is what we should always look for in our brewer at the end of the extraction,” Andrée explains.

“A flat bed is an indicator of correct pouring. It will help us ensure consistency in our recipe by creating even resistance in our coffee bed, which allows all particles to contribute at a similar extraction rate.”

The Bloom

The first phase of brewing is known as “the bloom”. This is when the water first comes into contact with the ground coffee in your dripper. At this point, it starts to release the gases (mainly carbon dioxide) which were absorbed by the beans during roasting. To ensure even extraction, it’s vital that as many of these gases are released as possible.

Jens Crabbé is the founder of MOK Specialty Coffee in Belgium, which has two locations in Brussels and Leuven. He says: “I suggest agitating during the bloom, to make sure the bottom of the coffee ‘cone’ is evenly saturated. This should be done swiftly to make sure all the coffee extracts evenly.”

Blooming coffee makes the resulting cup more well-rounded and gives it a “fuller” flavour. In comparison, coffee that does not adequately bloom has a weaker, flatter flavour with more acidity. This is because the unreleased carbon dioxide molecules stop the water from fully extracting the aromatic flavour compounds in coffee.

“[You can agitate coffee] by swirling the filter holder or by making a hole in the coffee cone and stirring after you pour the water,” Jens says. “The exact method does not matter that much as long as you are consistent.”

Creating a “well” in the dry coffee bed before pouring will allow for more even saturation, as water has easier and quicker access to the bottom of the grounds in the brewer. 

Jens says: “By making it easier to saturate all our coffee grounds with water during the [bloom], particles will extract at a similar rate into the final cup.”

A number of experiments conducted by James Hoffmann on V60 brewing techniques found that swirling during the bloom, rather than stirring, provided better tasting results. His videos recommend that brewers swirl until the slurry looks completely mixed, with no dry clumps.

Scott Rao’s updated manual pour over technique also suggests swirling during the bloom, but also recommends stirring areas where the coffee bed bubbles, as this makes it easier for gases to escape.

Agitation Throughout The Brew

After the bloom, you should continually stir or swirl your slurry to ensure even extraction. This decreases the likelihood of channeling occurring. Channeling is where water finds the path of least resistance through the coffee bed, which results in uneven extraction.

“Pouring gently and consistently is important,” Jens says. “This helps you extract the coffee evenly. 

“In the first stage of pouring after the bloom, you can [swirl or stir] to make sure the coffee gets pushed down from the sides of the filter paper.”

The Specialty Coffee Association Brewing Handbook states that “the brewing water must lift and separate each particle” in order to achieve even extraction. Throughout the duration of the brew, the slurry increases in volume as more water is added. As a result, agitation needs to be more forceful as the brew continues.

However, if you’re too forceful, the larger coffee particles – sometimes known as “boulders” – will move towards the sides of the filter due to the centrifugal force that pushes them outwards. 

James adds in his video that stirring the slurry in one direction, and then the opposite, helps to remove boulders from the walls of the brewer. 

“After swirling, you can gently tap your filter holder onto your container or vessel,” Jens says. “This way you will get the flat bed you’re looking for.” This final step levels the coffee particles in the slurry to produce a flat layer of wet coffee grounds for the last few moments of the brew.

Is Too Much Agitation A Problem?

When increased centrifugal force pushes the boulders outwards, smaller coffee particles move further down into the slurry. This affects extraction in one key way.

Timothy Bruno is a coffee expert and the author of the upcoming book Procaffeination: A Coffee Lovers Dictionary.

“Smaller particles have a greater relative surface area, and are always extracted to a greater degree, resulting in more bitterness,” he says. “Ideally, you want to make certain that the individual particles are properly extracted neither too little nor too much.”

If you are experiencing too many fines in your ground coffee, Timothy recommends adjusting your grinder.

“The amount of fines is a function of the grinding process,” he says. “You will definitely get a less even grind using a blade grinder than you will using a burr grinder.”

Additionally, tests conducted by Scott Rao found that the actual duration of the agitation itself altered the total brew time. In his test, seven-second spins resulted in a total brew time of 5 minutes 18 seconds, while two-second spins saw a brew time of 4 minutes 28 seconds.

This increase of 50 seconds could be the difference between evenly extracted coffee or an over-extracted, bitter cup.

Best Practices With Swirling And Stirring

Andrée highlights the importance of using a sufficient water-to-coffee ratio when agitating the coffee bed, especially during the bloom: “Some people find a 2:1 ratio to be enough, but I personally find this to be insufficient to saturate all grounds.”

James Hoffmann recommends no higher than a 3:1 water to coffee ratio, noting that too much water may prevent enough carbon dioxide from being released.

“Practice your bloom and your pouring techniques,” Andrée says. “This will help you obtain consistent and controlled agitation. If possible, use a sifter.” The more consistent your agitation techniques are, the more you will be able to identify, track, and alter your brewing variables.

Experimenting by adding or removing stages of agitation is the best way to hone extraction when swirling or stirring the coffee bed. If you find that your coffee is under-extracted, then agitate your brew more, but in a controlled manner; stir one more time, for instance, or swirl for just one or two more seconds.

Likewise, if your coffee is over-extracted, then reduce the amount of stirring and spinning in the bloom as well as later phases of brewing.

Andrée also advises considering the role of your grinder in the agitation process: “Improve your grind size distribution [by] ensuring your burrs are properly aligned and sharp,” he tells me.

“Some beans are [more] prone to generating fines; try a grind setting [that is] not too coarse but not too fine, so that your particles are as intact as possible for proper extraction.”

Coarser grinds tend to allow for more agitation with less risk of over-extraction, as fewer fines are produced and the particles are more evenly sized. However, grinding too coarsely will result in under-extracted, watery coffee.

Ultimately, both swirling and stirring pour over filter coffee can result in a great tasting cup. There is no single right or wrong answer; either can bring the best out of your beans.

However, it is always important to exercise caution and make sure your technique evenly extracts the soluble flavours from your ground coffee. By switching your agitation variables, experimenting to find the best technique, and tweaking it in very small increments, you will be in the best possible position to brew great tasting filter coffee.

Enjoyed this? You might also like Everything You Need To Know About Brewing Great Pour Over Filter Coffee

Photo credits: Birgit Sterckx, Tasmin Grant, Neil Soque

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Nothing beats a barista-made coffee from your local café. However, when the coffee shop is closed or you’re at home in your pyjamas, being able to knock up your favourite drink in your own kitchen is wonderful.

So, let’s explore how you make cold brew, filter, and traditionally espresso-based drinks at home, using the iconic AeroPress.

Lee este artículo en español Cómo Hacer tu Bebida Favorita de la Cafetería Con el AeroPress

Credit: AeroPress, Inc..

Brewing Coffee With The AeroPress

The AeroPress’ versatility, affordability, and ease of use have made it a firm favourite of many coffee lovers. It’s comprised of a chamber, plunger, and a filter cap. You attach the filter cap and a filter to the chamber, add the coffee and hot water, insert the plunger, and then push. Some brewers also like to use the inverted method, where they leave the coffee to steep before plunging.

By playing with different variables, you can bring out different flavours, aromas, and mouthfeels from your AeroPress-brewed coffee. You can emphasise its body and chocolaty notes, or bring out its sparkling acidity and fruitiness.

This is because not all coffee flavours extract from the ground beans at the same rate. When you add water to dry coffee grounds, the bitter compounds are the first to extract, followed by the ones responsible for sweetness, juicy acidity, and then finally, astringency.

Learn more in Understanding Coffee Extraction

Here are some variables you can play with:

• Brew ratio: this is the ratio of dry coffee to hot water. The more dry coffee relative to the water, the greater the intensity – but the flavour could become unbalanced. With the AeroPress, you’ll probably want to use 14–16g of dry coffee for 250g of water, but you always change this based on your preferences.
  
• Grind size: the finer the grind size, the quicker the coffee will extract. This is because you’re increasing the coffee’s surface area so it can better interact with the water. A finer grind size usually correlates with fruitier, juicier notes.
  
• Brew time: the longer the coffee steeps, the more time it has to extract. For this reason, you’ll probably want to pair a longer brew time with a coarser grind size.
  
• Water temperature: the higher the temperature, the quicker the coffee extracts.
  
• Agitation: stirring the water will typically speed up extraction. Even more importantly, it will make sure that all of the coffee is exposed to the water. However, it can be hard to control.

Find out more in this video from the World AeroPress Championship YouTube channel:

You might also like How to Brew Coffee at Home: A Beginner’s Guide

Espresso

The espresso is the heart of many of the drinks you can order in a coffee shop: lattes, cappuccinos, flat whites, macchiatos, and more. 

The AeroPress was designed to create an espresso-strength concentrate. AeroPress recommends that you use one scoop of fine or espresso-grind coffee and then add 175°F/80°C water up to the “1” on the chamber. 

Espressos often have an intense flavour and mouthfeel with a more chocolaty or toffee-like flavour, so that they taste good with milk. To achieve this, avoid exacerbating extraction through heavy agitation of the coffee. If you find that your brew tastes too fruity or acidic, reduce the grind size and increase the brew time to match.

You will probably also prefer a medium or medium-dark roast, as this is what is typically used for espresso.

Filter or Drip

Drip and filter coffee tend to have greater clarity and a less intense mouthfeel than espresso. This is because the filter traps much of the coffee’s oils, preventing them from entering into your cup. The thicker the filter, the less oil can seep through. 

The AeroPress is already a filter brewing method, but to increase your clarity and get more of that batch brew or drip flavour, try doubling up your filters. Although they are environmentally friendly, you should also avoid metal filters. 

Pour over brew methods, such as the Chemex, Kalita Wave, and Hario V60, are used in specialty coffee shops to highlight the fruity and floral notes of high-quality coffee. If you want this effect, aim for a fine grind, short brew time, hot water, and lots of agitation.

Of course, you won’t be able to extract citrus or jasmine flavours if they’re not present in the original coffee. Try light and light-medium roasts and check the flavour notes on the coffee bag.

Latte

Every coffee shop has its own recipe. However, a latte is typically around 8 oz/230 ml and made with steamed, stretched milk.

Start by creating your espresso-like concentrate in the AeroPress. Then, you’ll need to heat your milk. If using dairy, opt for fresh, full-fat milk. If opting for non-dairy milk, oat and almond are the two most popular types for coffee.

Read more in What’s The Best Non-Dairy Milk For Specialty Coffee?

You have a few options for the next step. You could use a milk steamer or frothing wand, or you could heat the milk on the stove or in the microwave before using a balloon whisk to aerate it. 

If using a milk steamer or frothing wand, make sure to keep the tip under the surface of the milk. This will prevent you from creating cappuccino-like foam. Tilt the jug or cup at an angle while steaming. And after you’ve done, tap and swirl the jug to disperse any large bubbles.

Finally, steadily pour the steamed milk over your espresso, and enjoy.

Cappuccino

Although often confused with a latte, a cappuccino is a smaller beverage that contains foamed as well as steamed milk. While steamed milk is silky and smooth, foam is drier and stiffer.

You may have heard that a cappuccino should be one-third espresso, one-third steamed milk, and one-third foam, that’s not necessarily true. Experiment to find out what you like the most.

You might also like What Is a Cappuccino & How Has It Developed Over Time?

To make a cappuccino-like drink with your AeroPress, start by brewing your coffee and heating your milk, just as you did for the latte. Then, to create the foam, you’ll want to introduce more air into the milk. If using a frothing wand, place the top just below the surface of the milk. Once you’ve got a good amount of foam, you can then dip it further into the milk to make sure it’s evenly heated.

When pouring your milk, hold the foam back with the spoon so that just the steamed milk runs into the cup. Then use the spoon to heap the foam on top.

Flat White 

Another milk-and-espresso beverage, the flat white is a great choice for those who want their coffee to taste stronger. Although recipes vary according to the coffee shop, it’s typically the same size as a cappuccino but with a double espresso shot and only a tiny layer of microfoam.

When brewing your coffee, you’ll need to use double the amount of dry grounds and water. Remember to keep the ratio the same to ensure that the flavour and extraction level don’t change.

Americano

An Americano, or espresso diluted with hot water, creates the rich flavour of an espresso but without the bold mouthfeel. It’s typically made with one-part espresso for two-parts hot water, yet there’s no need to stick to a hard-and-fast rule. Brew your espresso-like concentrate with the AeroPress and then experiment with different quantities of hot water to see what you prefer. 

While you should pay close attention to the water temperature you use in the AeroPress, the temperature of the hot water you then add to the brewed concentrate doesn’t matter. 

Cold Brew 

Cold brew normally takes 12–24 hours to make, since coffee needs a long time to extract in cold water. Yet the AeroPress official method is just two minutes long.

Take one scoop of finely ground coffee, add room-temperature water up until the “1” mark, and then stir non-stop for one minute to increase the extraction. Finally,press gently and dilute your drink with ice-cold water or milk.

Read more in How to Make Cold Brew Coffee in an AeroPress

The AeroPress might not be able to bring out as much crema on your espresso as a barista could, or create latte art-worthy steamed milk. 

However, by tweaking brewing variables such as grind size, brew time, and water temperature, you can bring out many of the different textures and flavours present in lattes, pour overs, and even cold brew. And that sounds pretty great to us.

So, what are you waiting for? Grab your AeroPress and start grinding your coffee.

Enjoyed this? Read How to Store Coffee at Home

Please note: This article has been sponsored by AeroPress, Inc.. 

Photo credits: Credit: AeroPress, Inc.

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The post How to Make Your Coffee Shop Favourites With The AeroPress appeared first on Perfect Daily Grind.

Lee este artículo en español Breve Historia de Los Métodos Manuales de Preparación de Café

Whether you’re a home brewer wanting to know more about which device to invest in, or a barista looking to better understand the origins of the device you use every day, you’ll benefit from knowing the history of the following manual brewing devices. 

Here’s how approaches to manual coffee brewing have changed over time, as well as the most popular devices that dominate the market today.

A kettle and thermometer, both used to brew coffee. Credit: Neil Soque

The Beginning of Manual Brewing

While there are no records that tell us exactly when or where people started consuming coffee, most agree that it originated in or near what’s now known as Ethiopia. According to Catherine M.Tucker’s book, Coffee Culture: Local Experiences, Global Connections, the first people to use coffee may have been ancestors of Ethiopia’s Oromo people, who according to early European travellers, mixed ground coffee cherries and beans with animal fat to create “long-lasting, calorically dense food balls”.

As the 15th century came to pass, Turkey’s Ottoman Empire expanded its reach to include parts of North Africa, Central and East Europe, and Asia. This allowed them to control the main trade routes between Asia, Africa, and Europe. It is here that they likely encountered coffee.

After being introduced to the drink, the Turks invented one of the earliest methods of manual brewing coffee. Roasted beans were ground using mortars, added to water, and then boiled in a pot called a cezve. Soon, this brewing method spread from the Sultan’s kitchen to wealthy homes across the Ottoman Empire, until the entire population was enjoying it.

While the Ottoman Turks attempted to keep a monopoly on coffee trade by banning its export, maintaining this proved impossible. The seed was smuggled out of the country and eventually enjoyed across Europe, where various European governments looked to African colonies to provide coffee to meet the growing consumer demand. 

As colonial expansion spread, so did the reach of coffee, and by the 18th century, it was a popular beverage drunk across the world. While at this point it was only enjoyed by the wealthy elite, time – and the invention of affordable and easy to access manual brewing devices – would soon result in it being enjoyed by all. 

You may also like Melitta, Chemex, & More: A History of Pour Over Coffee

Coffee being brewed on a V60 at a coffee shop in Berlin, Germany. Credit: Julio Guevara

Early Manual Brewing Devices

When coffee arrived in Europe, it was usually prepared by adding ground beans to water in a single pot and boiling it, which is similar to how the Turks enjoyed it. It entered the continent at the same time as the Industrial Revolution was taking place. At the time, most people drank beer or wine as a safer alternative to water. The introduction of coffee allowed people to participate in factory work unhampered by the usual side effects of inebriation. 

In the 19th century, the drip method of preparation was developed in France and became dominant. With this method, ground coffee was placed in a container situated between two chambers of a pot, with heated water added to the top chamber. It then percolated or dripped down through the coffee into the bottom serving receptacle. 

It was in this century that domestic preparation of coffee took off in earnest. In 1908, a German woman named Amalie Auguste Melitta Bentz invented the first coffee filter, which allowed her to brew coffee without sediments and with a clearer taste. She patented her paper filter idea and established the Melitta company in the same year.

Melitta and her husband presented her filters at the 1909 Leipzig Trade Fair, where it was successful. After some adjustments were made, a cone-shaped filter was created, which became popular due to its improved design.

A cup of black coffee. Credit: Julio Guevara

The History of the Moka Pot

As coffee spread its reach across Europe, France and Germany weren’t the only countries to dabble with creating manual brewing methods. While the 18th century saw large-scale mechanical espresso machines being patented, Italy’s 19th-century economic boom saw locals demanding ways to enjoy a similar quality coffee, efficiently, and at home. 

It was in 1933 that Alfonso Bialetti invented the Moka Pot. Designed for use on a stove, the pot had three parts. It passed boiling water that was pressurised by steam through a funnel and ground coffee into the top chamber. 

It was an instant success and is still produced by Bialetti today, even as the company experiences increased competition from coffee pod machines and other devices.

You may also like How The Moka Pot Influenced Coffee Consumption

A coffee carafe and cup on a table. Credit: Neil Soque

The French Press

Several years before Alfonso Bialetti invented the Moka Pot, two Frenchmen were creating an early version of the French Press. In 1852, Mayer and Deforge patented a design of this type of brewer, which differed significantly to the one we currently use, as it lacked a seal inside the carafe.

It was in 1929 that two Italians, Attilio Calimani and Giulio Moneta, patented a design for the coffee maker resembling the French Press that we know today. This version included a seal around the plunger disks, keeping them flush with the receptacle and making plunging more efficient.

It was only in 1958 that the most popular design of this brewer was patented, and it was done by a Swiss man called Faliero Bondanini. As it was manufactured in France, it grew in popularity there and was called the Chambord.

This particular version was a total immersion device, which means that the ground coffee is in full contact with hot water for around four minutes when the plunger is pushed down. During pouring, the filter keeps the grinds in the carafe, creating a clean and full-bodied cup of coffee.

While no single company dominates production of the device, the Danish tableware and kitchenware company Bodum has been manufacturing their version of it since 1974, with huge success. Their version is called the Bistro and is available from retailers around the world.

Learn more in French Press – The History & Brewing Guide

A cup of black coffee. Credit: Julio Guevara

The Chemex

In 1941, German chemist and inventor Peter J. Schlumbohm created the Chemex, which was one of many inventions he created in his lifetime. Having renounced his place in his family’s chemical business, his years spent earning a PhD in Chemistry at the University of Berlin formed the foundation for his future inventions. 

He first exhibited a prototype of the Chemex coffee maker at the New York World’s Fair in 1939 and formed the Chemex Corporation two years later to manufacture and market it.

Schlumbohm considered the appearance of his inventions to be very important, and his educational influence is apparent in the Chemex’s resembling chemical laboratory apparatus. Its style resembled that of Modernist designers, and it was endorsed by the Museum of Modern Art.

Using a pour over method, the Chemex works by passing water through a bed of coffee and a paper filter. As the filters are usually 20-30% heavier than typical filters, they retain more suspended oils during brewing and keep out more solids, resulting in a cleaner cup of coffee.

Learn more in Chemex – The History & Brewing Guide

A Chemex collar. Credit: Fernando Pocasangre 

The Kalita Wave

Kalita Co. is a Japanese company that has been producing coffee equipment and paper filters since the fifties. They created the Kalita Wave series of coffee drippers in 2010. The device looks similar to the V60 at first sight but has several key differences.

Unlike a V60, the Kalita Wave has a flat bottom with three extraction holes, which eliminates any channelling of water in the coffee bed and slows down the water’s flow through the coffee grounds, for a crisp cup of coffee. The dripper has little contact with the filter, keeping the temperature consistent and dispersing the water evenly. 

Thanks to its flat bottom, water flow is restricted in a more stable and predictable way than with other manual drippers. This creates a flatter bed of grounds, for a more even extraction of flavour. 

Available in metal, the Kalita Wave is stove-top friendly (like the Moka Pot). It is also available in glass and ceramic.

Read more: Kalita Wave: The Story & Brewing Guide

Coffee being brewed on a Kalita Wave. Credit: Neil Soque

The Hario V60

The Chemex isn’t the only manual brewing device to originate from a chemistry background. The Hario V60 was created by a Tokyo company that produced and sold physical and chemical-use glass products. It’s a relative latecomer to the manual brewing device industry, having only been invented in 2015, and it gets its name from the 60º angle of its cone. 

The V60 has three qualities that impact its brewing ability. Firstly, its cone shape lets the water poured over flow towards its centre, for longer contact time with the grounds. Secondly, its single hole means that the flavour of the coffee can be altered by changing the speed at which the water is poured in. Finally, the cone has spiral ribs on the inside, which allows more air to escape and maximises the expansion of the coffee grounds.

The V60 was first introduced in ceramic and glass, then plastic, and finally metal. It was also released in a copper version, for higher thermal conductivity. This allows for better retention of heat and therefore better extraction.

Read more: Hario V60: The History & Brewing Guide

Barista brewing pour over coffee using a V60. Credit: Fernando Pocasangre 

The AeroPress

The AeroPress was created by engineer Alan Adler in 2005 and is a notable brewer to come out of the USA. Made of polycarbonate, it contains no BPAs and phthalates and features its brand name lettering in gold, for easier detection of possible counterfeits. 

Adler’s invention was created out of a need for a less bitter cup of coffee. He realised that for this to happen, brewing time would need to be shortened. He created a closed chamber to increase the pressure required during brewing, which also resulted in a much faster brewing time, compared to most manual devices on the market.

Being compact, portable, and easy to clean, the AeroPress has carved out its own niche in the industry. It now has its own championship too, with the World AeroPress Championship drawing entries from across the world every year.

Coffee is brewed using an AeroPress. Credit: Fernando Pocasangre 

Manual methods have opened a path towards more experimentation for home brewers and coffee shops alike. For both groups, there are no hard or fast rules for how they’re used to brew coffee.

Knowing how each one was created and works will not only allow you to better enjoy the beverage but also to respect the efforts that have been put into creating each device – whether you’re enjoying it at home or using it to serve others.

Enjoyed this? Then Read Everything You Need to Know to Brew Great Pour Over Coffee

Written by Miguel A. Hernández Zambrano. Feature photo: Freshly brewed coffee in a carafe. Feature photo credit: Neil Soque

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Perhaps you have a go-to recipe for making an excellent V60. However, if you change from a light roast to medium, you may have to rethink it. Read on for some insights into how to adjust it for your coffee roast profile.

You may also like our article on whether you should brew experimentally processed coffees differently.

Coffee beans cooling down after being roasted

How Coffee Roast Profiles Vary

Roasted coffee is generally divided into light, medium, and dark. You likely have a go-to roast profile that you prefer for a brewing recipe. But what’s the real difference between them? 

There’s no industry standard for light, medium, or dark roasters often use their own names for different profiles. Generally, light roasts retain more of the coffee’s flavours, emphasising floral and citrus notes.  Darker roasters roasted overwhelm these subtle flavours with chocolatey, nutty sensations. If a very dark roast can become bitter.

Flavour isn’t the only difference among roast profiles. The more heat a coffee is exposed to in a longer or hotter roast, the more porous and soluble it becomes. It’s partly why we use medium or dark roast coffees to make espresso. Because there’s only a short window of time for extraction, a soluble roast will work better than a light roast.

Roasted coffee beans in a bag. 

Why Should You Brew Light & Dark Roasts Differently?

A good cup of coffee depends on having the correct extraction levels. When you introduce coffee beans to water, it extracts a number of their chemical compounds. The compounds responsible for fruity notes and acidity are extracted first. It then extracts sugars to produce sweet flavours, and then the compounds that create bitterness. Underextracted coffee can taste sour because the sugars haven’t yet extracted, and overextracted coffee can be bitter. This will impact your brewing recipe.

Because light roasts are less porous than darker ones, their compounds extract more slowly. It’s why light roasts are often brewed slowly using a pour over – the beans have more time in the water than in a quick brewing method such as espresso. It also means that if you use the same brewing recipe and coffee but two different roast profiles, you’d experience different flavours and mouthfeel.

Sam Koh is a barista and the founder of Kaffiend Brews, a coffee shop in Singapore. She tells me that “a light roasted coffee gives you more intricate notes, and these can be best accentuated through a slower brew such as a pour over. A darker roast may not shine through a slower brew due to its extraction rate, creating more acrid or bitter notes.”

Roasted beans in a cup. 

How to Tweak Your Brew Recipe For a Different Roast Profile

So, you have a brewing recipe figured out but want to try new beans. How can you adjust your method to fit a different roast profile? To compensate for differences in porosity and solubility, you can change a few variables.

Grind Size

When coffee is ground finer, it has more surface exposure. This means that extraction will happen more quickly. So if you’re used to brewing with a medium roast and are trying out a light roast, grind it a little finer. Likewise, if you usually use light-roasted beans, but are going darker, use a coarser grind size.

Marlous Van Putten is a store manager and barista with Dutch coffee shop chain Coffeecompany. She says, “I personally also always grind my beans finer if they’re a lighter roast and dark roasts on the coarser side. This is because dark roast tends to be more bitter in flavour to begin with, so a longer contact time between water and coffee would result in over extraction.”

Check out our article on how you can brew coffee with the AeroPress using different grind sizes.

Freshly ground coffee beans are poured into a Chemex. 

Water Temperature

There is no one correct temperature for brewing coffee (although there are recommended ranges, such as the SCA’s suggestion of 195–205 °F/90–96°C). But the hotter the water used, the faster the extraction. Some compounds will never be extracted at very low temperatures, which is why cold brew tends to be very mellow and sweet but can lack any bitterness to balance out other notes.

Consider water temperature as one more factor you can adjust to bring out your preferred flavours in your coffee when using a specific brewing recipe. If you’re using a dark roast, you may want to lower the temperature of the water to avoid over-extraction and reduce the chance of bitter flavours. If you’re using a lighter roast than usual, using hotter water will help speed up extraction a little.

Marlous says, “The normal rule is lower temperatures for darker roasts and higher temperatures for lighter roasts. Side note to this is that darker roast probably won’t taste good if it’s made with water at high temperatures, whereas lighter roast can taste good made with lower temperatures.”

You may also like our article on why thermal stability is important for manual coffee brewing.

Coffee brews in a Chemex. 

Brewing Time

The longer the coffee is exposed to water, the more time there is for extraction to take place. Keep this in mind when choosing a brewing method – as discussed, espresso only has a very short opportunity to extract so a light roast might not be the best choice. 

Within each brewing method, you can also tweak your technique to provide a longer or shorter brewing time. For example, by pouring water more slowly when making filter coffee, or by letting a French press sit for longer before serving.

Sam says, “For coffee that is of a lighter roast, I find that letting it steep longer before first drip gives the coffee more time to exude more complex and intricate flavors.” 

Coffee being brewed on a Chemex. 

Other Factors That Could Impact Your Brew Recipe

It can be interesting to use different roast profiles with various grind sizes, water temperature, and brewing time and see how these variables impact your cup. But you should also consider what features can change accidentally with your brewing recipe.

As coffee beans age, flavour degrades. Oxidation and degassing cause the coffee to lose the important oils and compounds that contribute to body, aroma, and flavour. It’s generally recommended to use roasted coffee beans within two weeks after buying them, to store them in air- and light-tight containers, and to grind them as needed to avoid even faster oxidation.

Coffee beans being weighed on a scale before brewing. 

If you know your beans are a little old, you can adjust the brewing recipe to compensate. By grinding light roasts finer, you’ll increase the surface area and the rate of extraction, which should liven up slightly stale beans.

Old dark roasted beans can be very porous and therefore very soluble. Grinding a little coarser or using cooler water will slow down extraction and avoid the brew becoming too bitter.

Marlous recommends keeping in mind a few other factors that may make or break your end result. “What kind of water you use, the freshness of the beans, the quality of the beans, the cleanness of your equipment,” she says. “You have to be aware that every step of the process has an effect on the outcome of the cup.”

Freshly ground coffee.

Perhaps you have a brewing recipe that you’ve developed through controlled experiments or trial and error. But when you try a new roast profile or beans from a different roaster, it’s time to rethink your method. By understanding how variables including grind size, brewing time, and water temperature can be adjusted, you can get great results with every roast profile.

Enjoyed this? You may also like our article on whether we need to rethink the relationship between grind size and coffee extraction.

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The post Adjusting A Brewing Recipe To Your Coffee Roast Level appeared first on Perfect Daily Grind.

To find out how to make cold brew with an AeroPress, along with some tips and tricks for better flavor and extraction, I spoke to the brewing device’s creator, Alan Adler. Here’s what I learned.

Lee este artículo en español Cómo Preparar un Café Cold Brew Con un AeroPress en 2 Minutos

The AeroPress, complete with stirrer and filters. Credit: AeroPress

Cold brew AeroPress coffee in minutes

Look up most cold brew coffee recipes, regardless of the brewing device, and you’ll see steep times of 12 hours, 24 hours, or even longer. Traditional coffee-brewing involves heat, and for good reason: it is this heat that speeds up the chemical reactions, allowing the flavor and aroma compounds from the coffee grounds to be extracted into the brew. To compensate for the cooler temperatures, most recipes call for longer brew times.

It’s worth mentioning that cold brew has a reputation for being sweeter and more mellow than hot-brewed coffee. This is because some chemical compounds cannot be extracted at cooler temperatures. However, with time or another exacerbating factor, you can still get a delicious – and refreshing! – beverage. 

This makes the short steep time of the AeroPress cold brew remarkable. Alan tells me, “I expected to gradually increase the steep time until the brew was satisfactorily rich. 

“So I started with our standard time and was pleasantly surprised that it was satisfactory, though about 10% weaker than hot brew. Very few people can taste such a small difference. But the easy way to restore that small difference would be to use 10% more coffee. Standard is a heaping scoop or about 16 grams for an 8 oz serving. So about 17.5 grams would restore the difference. 

“But Alex Tennant, our general manager suggested increasing the stir time instead of using more coffee. We tried the standard 10 seconds, 30 seconds, 1, 2 and 3 minutes. 1 minute was enough. There was very little difference beyond a minute.”

In other words, the intense agitation increases the extraction and results in a faster brew time – perfect for when the weather’s hot and you want a cup of cold brew right now. But let’s take a closer look at how you prepare it.

Learn more about extraction in Understanding Coffee Extraction

Cold brew coffee prepared in an AeroPress. Credit: Fernando Pocasangre

How to prepare cold brew in your AeroPress

The AeroPress is famous for its simplicity. Forget concentric circles and multiple pours, you simply add coffee, add water, stir, and press. Fortunately, making cold brew is similarly straightforward – although with plenty of room to experiment as you find your ideal recipe. 

1. Set up your AeroPress 

Whether you prefer brewing with the traditional or inverted method, the first step to good cold brew is preparing your AeroPress. You should begin by making sure it is clean and dry.

Next, set up the AeroPress and place a filter in the cap. It’s a good idea to rinse your filter with hot water once it’s in place. This will help it adhere to the cap and also reduce any paper flavors. Some people also like to experiment with doubling up on filters or using metal ones. Metal ones will allow more of the oils through, creating greater body, as well as resulting in less waste. Paper filters, on the other hand, will create a cleaner and lighter brew as they keep all the oils out. 

Read more in Inverted vs Traditional: A Video Guide to Choosing Your AeroPress Brew Method

Different AeroPress filters. Credit: Fernando Pocasangre

 2.  Prepare your coffee & add it to the chamber

The AeroPress’ beauty lies in its versatility. You can use it with a wide range of coffees and experiment with grind size, steep time, brew ratio, and more. As Alan says, “AeroPress works well with any type of coffee… The most popular roast is medium, which I think has the best flavor, but you can decide what you like.” 

He adds, “I currently drink medium roast Yirgacheffe. Prior to that, it was mostly Guatemala.”

Yet despite the AeroPress’ flexibility, there are some guidelines to follow. The cold brew recipe calls for a fine grind. When brewing coffee, the finer the grind, the quicker the flavor and aroma compounds will extract. Coarser grinds are best suited for recipes with long steep times. 

Even when brewing with hot water, Alan recommends being careful with an overly coarse grind size. This is because it leads to more drip-through before you begin the press. “If the drip-through while stirring is more than about 3 mm, you might want to try a finer grind or use slightly more coffee… Large quantities of drip-through reduce brew strength,” he explains. “Some people worry about even small amounts, but I’ve researched this and determined that less than 3 mm has no detectable reduction in strength.”  

Dosage is another variable you should consider. Alan tells me that the standard is “16 g for an 8 oz serving.” If you want to experiment, start with this dose and then slowly adjust it until you find the recipe you like best. As Alan says in his inventing classes, you should “try things even if you don’t expect them to work.” This is how you discover new things.

Read more in A Guide to Coffee Grind Size, Consistency, & Flavor

Adding freshly ground coffee to the AeroPress. Credit: Fernando Pocasangre

3. Add water

According to the official AeroPress recipe, a standard AeroPress coffee should be brewed with 80ºC/175ºF water. Then you should stir the coffee grounds and water for about 10 seconds before pressing.

For cold brew, you should add tap or room temperature water up to the number two mark (which, by my calculations, is around 130 grams of water). Some people also choose to use filtered water, because certain minerals commonly found in water can slow down or speed up extraction. 

This amount of water should be enough to create a coffee concentrate, which will be the base of your cold brew. Alan tells me, “Pressing the concentrate and then adding water makes a smoother cup… than pushing all the water through the grounds,” he says. 

Once you’ve added the water, stir for a whole minute. Don’t be tempted to skip this step, or you’ll be left with a weak drink.

You might also like AeroPress Coffee Guide: How to Brew For Different Flavour Profiles

Stirring the steeped coffee. Credit: Fernando Pocasangre

4. Press

“Pressing gently is the fastest press,” Alan advises. He explains that pressing hard can compact the coffee particles into a barrier, making your work even harder. If you start to feel too much resistance, so that it becomes hard to keep pressing, pause for 10 seconds. 

Once you’ve finished the press, you can now remove the ground coffee from your AeroPress and clean the device.

Pressing the AeroPress to create a cold brew concentrate. Credit: Fernando Pocasangre

5. Add more water 

Now that you have your coffee concentrate, you can proceed to add chilled or icy water to make an 8 oz cup/237 ml cup of coffee. Alan tells me that room-temperature water will also work well if you don’t have access to ice or a refrigerator. Again, you may wish to use filtered water. 

Serving AeroPress cold brew over ice. Credit: Fernando Pocasangre

On a hot day, there are few things as refreshing as a cold brew. With this AeroPress recipe, you can skip the 24-hour brew time and start sipping on your coffee in less time than it takes an electric kettle to boil. Just make sure to use a fine grind and stir well before pressing.

Enjoyed this? Read AeroPress Coffee Guide: How to Brew For Different Flavour Profiles

Please note: This article has been sponsored by AeroPress, Inc.  

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The post How to make cold brew with an AeroPress in two minutes appeared first on Perfect Daily Grind.

Brewing method also has a role. You’ll likely make different roasting choices dependent on whether the coffee will be used to make an espresso or a pour over. But why and how do we roast differently for filter coffee and espresso? Read on to find out.

Lee este artículo en español La Diferencia Entre Tostar Para Café Filtrado y Para Espresso

Inside a coffee roasters. Credit: Neil Soque 

Why Have Separate Filter & Espresso Roasts?

Espresso and filter coffee are fundamentally different brewing methods. When preparing an espresso, we force hot, pressurised water through a compact puck of coffee. There is an extremely short opportunity for extraction, so we use finely ground coffee and very hot water to allow the compounds in the coffee to extract quickly.

With filter coffee, there is longer opportunity for extraction so we tend to use a coarser grind than in espresso and water that is lower in temperature. In a pour over, a larger volume of water is allowed to absorb the compounds at its own consistent time and pressure, instead of by force. The result is coffee with lower acidity and less body than an espresso made with the same beans.

Learn more in Espresso vs Filter: What’s The Difference?

Bags of green coffee ready to be roasted. Credit: Ana Valencia

Coffee that is roasted dark is more porous than light roasts. This means that medium and dark roasts are more soluble, extract more quickly, and may be better suited to different brewing methods than light roast.

Of course, we can adjust variables such as grind size to compensate, but the general rule is that a light roast works best with a slower extraction method, such as a filter coffee, and a darker roast with a quick method such as espresso. This is because of the differences in solubility. But it’s not always that straightforward.

“You can have filter coffee that’s dark, espresso that’s light, and vice versa,” says Trey Cobb, Co-Founder of Greater Goods Coffee Roasters in Austin, Texas. “In some cases we’ll roast the same coffee that may perform best for filter or espresso with the same end temperature but the roast profile is drastically different. It’s down to what you want to convey in the coffee, knowing how it’ll be brewed.”

Brian Webb is a roaster and SCA Trainer at Pacific Coffee Research in Kona, Hawaii. He says, “I generally approach roasts for filter brewing and espresso in very different ways. A fast, light profile that presents floral notes and sparkling acidity in a filter brew might be unpleasantly tart and funky in the espresso machine”. 

This difference would be caused by different rates of extraction. Fruity and acidic notes are extracted first, followed by sweetness, and then bitterness. So if a coffee doesn’t have enough opportunity for the sweet compounds to be extracted, it will taste tart.

Learn more in Understanding Coffee Extraction For Your Perfect Cup

 A bag of roasted coffee beans. Credit: Nadia Valko 

How to Roast For Different Brewing Methods

With espresso, light roasts are at risk of being under-extracted and tasting sour. So many people roast darker for espresso, to ensure the beans are very soluble. But there are roasting techniques that allow the beans to become more soluble without being dark roasted.

“The most common misconception I encounter among novice roasters is that well balanced espresso requires a darker roast,” says Brian. “This is not always true. I almost always roast slower for espresso compared to filter, but almost never go darker.”

You may also like Roasting For Sweetness, Decaf & Otherwise: A Practical Guide

A carafe of freshly brewed filter coffee. Credit: Neil Soque  

Lukasz Jura is the owner of Coffee Proficiency, a green and roasted bean supplier in Krakow, Poland. He says, “Filter roasts are usually more dynamic and shorter. That helps us to preserve origin flavours in our final products. Espresso is a bit different, because we need coffee to be a little more brittle, easier to extract and control. That’s why we roast [these coffees] with longer development time.”

Brian says, “Don’t rely entirely on cupping when developing espresso profiles. Things change dramatically when you put your coffee under nine atmospheres of pressure, so make sure you taste your espresso as espresso.”

Freshly roasted coffee spills out of the roaster. Credit: Battlecreek Coffee Roasters

• Roasting for Filter

Filter coffee highlights a coffee’s individual flavour notes, so roasting for filter should focus on preserving the specific characteristics of that coffee. Generally speaking, the longer beans spend in roast development, the more body the coffee will have, but the more acidity and fruitiness will be sacrificed. 

In general, coffee that endures a longer development stage will have more caramelisation and sweetness. If you want to highlight fruit flavours, roast with a shorter development stage. For a more chocolatey flavour, try keeping it here a little longer.

Roasted coffee beans. Coffee and I 

Trey says, “We have a lot of customers who judge our coffee based on a pour over or batch brew,” he says. “The goal is a profile that balances acidity with sweetness and builds ample body. We like a layered flavour profile and a distinct start, middle, and finish.”

He tells me that there is no one roasting profile that creates an ideal filter roast. “We want the coffee to take the drinker on a journey as it cools, not one that screams one primary note and then falls apart. How we get there differs with each coffee but we can usually land on a profile that achieves this goal.”

Freshly roasted coffee in cooling tray. Credit: Devon Barker

• Roasting for Espresso

Espresso roast needs to be more soluble than filter roast, but how do you achieve this? Several roasters told me that they use a longer roast than with filter coffee, but don’t necessarily increase the temperature or create a dark profile.

“When roasting for espresso, we think about opening the window of ideal extraction [through solubility] and how the acidity will be amplified,” Trey says. “Often that requires a longer roast to further break down the bean and its chemical compounds. Maybe that’s post crack development, maybe before first crack, or a combination of both. We typically find the latter is the case.”

“On the cupping table, it may not be as balanced or dynamic but so long as the sweetness is dominant, we find it works well when brewed as an espresso, which highlights the acidity to finish out the end result.”

Shots of espresso. Credit: Neil Soque 

Lukask says that extended development time makes coffee “more delicate” but easier to extract in a shorter brewing time. “It changes coffee a bit so it’s easy to recognise the roast characteristics on a cupping table, but when you brew it properly, you can enjoy well-developed and extracted coffees,” he says.

Brian tells me, “I’ll typically roast to the same time and temperature post-first-crack, but I’ll extend the Maillard phase for espresso in order to develop more pleasant bitterness and base-notes which help to maintain balance under pressure.”

Coffee beans and ground coffee in portafilters. Credit: Zarak Khan

What About Omni Roasting?

Omni roasting is when you roast beans to be brewed in any method. This doesn’t mean that the coffee will always taste the same – brewing method will still impact flavour and body. But in theory, omni roasted coffee will taste good prepared as both filter and espresso.

Brian says, “From a business standpoint, I like it a lot. It saves on labour, packaging costs, and eliminates a lot of logistical burden in the roastery. I don’t think it’s always going to lead to the best presentation of a coffee though”.

In omni roasting, you’re likely to want a middle-ground amount of time in development. This will allow the beans to become soluble enough to work in an espresso but preserve a range of flavour compounds to allow the coffee to taste balanced with any brewing method. 

As with all roasting, each coffee will have different characteristics and you should sample a variety of profiles in test roasting. With omni roasting, try each profile with several different brewing methods.

Roasted coffee drops into the cooling tray. Credit: Neil Soque 

Trey tells me that omni roasting “appeals to home consumers who may or may not have an espresso machine at home”.

“When we’re selling online or through our cafés, we don’t know how they’re going to brew it,” he says. “Omni roasting gives us a firm middle ground to hopefully appeal to a larger portion of the market. It also helps with our wholesale customers, one of whom may choose to batch brew a coffee while another runs it as their featured espresso.”

But he acknowledges that omni brewing may not allow the best qualities of a coffee to shine. “Omni roasting can lead to the coffee underperforming for some customers and baristas, who are judging us as a roaster based purely on their preferred brewing method. It’s tricky when trying to impress a new potential account.”

Lukasz tells me, “I’ve never done an omni roast that I was happy with both as filter and espresso. I’m not saying it’s impossible to achieve, but so far for us it’s always been best to roast separately for filter and espresso.”

Find out more in Omni Roast: Is There One Roast to Rule Them All?

A roaster checks the beans. Credit: Battlecreek Coffee Roasters

There’s no one roast profile for espresso or filter and each batch of green coffee beans will have its own qualities. But by understanding extraction and roast development, you can make a more informed choice of whether to roast differently for espresso and filter. 

Regardless of whether you choose different roast profiles or to go with omni roasting, it’s important to cup regularly. You should also sample brew the coffee with the method it’s intended for. By paying close attention, you’ll be able to roast delicious coffee for any brewing method.

Enjoyed this? You may also like What Happens During Coffee Roasting: The Chemical Changes

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We tend to split filter methods into two categories: pour over or drip and immersion. But what are the differences between these two styles?

I reached out to James Gray, the co-founder of Barista & Co., to find out. His team are Kickstarting the Twist Press, a version of the iconic coffee press that users twist rather than press. James shares with me his insights into the two types of filter coffee.

You might also like Everything You Need to Know to Brew Great Pour Over Coffee

Decanting freshly brewed French press coffee.

What’s the difference between drip and immersion brewing?

The humble drip coffee is a style characterised by pouring hot water over ground coffee. It allows gravity to draw the water through the coffee bed and filter into a vessel.

It includes devices like Hario V60, Kalita Wave, Chemex, as well as most batch brewers on the market.

However, the term “pour over” does not apply to batch brewers. It only applies to manual drip brewing, where the water is poured by hand onto the ground coffee.

Brewed coffee drips through the flat-bottomed Kalita Wave.

Why do we love drip coffee?

“With gravity-driven coffee, one of the things you can end up with is a very, very complex coffee, which has… a great deal of flavour [and] a lot of depth to it,” says James.

Drip brewing lends itself well to highlighting the complexity of a coffee. It tends to accentuate delicate flavours and aromas. Because the water can extract coffee oils and solubles in its own time, it also allows for greater flavour clarity

Depending on the flavours you want to highlight, different pour over devices can reveal different characteristics, even the same coffee.

For example, the V60 is good for emphasising acidity and floral notes while still letting a decent amount of coffee oils through the thin filter, boosting body. The Chemex, with its thick filter paper, retains more of the beans’ oils and so yields a sparkling brew with complexity. The Kalita Wave, with its flat-bottomed base and three exit holes, tends to suspend the brew for longer with a reduced flow rate, resulting in a more forgiving coffee and a deeper sweetness.

With drip brewing, the extraction of coffee solubles is also a little more efficient than immersion brewing, due to the constant flow of water, as Matt Perger of Barista Hustle explains. In other words, you need marginally less ground coffee per brew.

The actual filter, depending on material and thickness, also traps the resulting coffee oils outside of the brew, yielding a clean-tasting coffee. This makes it a good choice for coffees with highly complex profiles, such as high-quality single origins or ones with a nuanced acidity.

Last but not least, drip brewing devices tend to be relatively easy to clean.

Coffee is brewed with a Chemex.

Drip coffee: the challenges

“The main challenge that you have with this [method of brewing is that] consistency is very difficult,” says James.

In a tool with so much flexibility, human error can cause problems. Bad pour technique, channelling, and temperature instability are common issues that affect drip brews. Beginners can find controlling the rate of pour with a gooseneck kettle difficult, if they have one at all.

Channelling is the result of unevenly distributed grounds; it causes the water to channel through certain sections of the coffee bed, over-extracting there, and not extracting or under-extracting in other sections. The deep angle on some pour over devices, like the Chemex and the V60, makes it more difficult to evenly distribute coffee grounds. This can result in an unbalanced brew with jarring notes.

“You can argue that when you move from certain brands to other brands, you know, the shape of the filters and things like that will aid you in terms of consistency…” James says. “But ultimately… you’re still going to carry a risk of channelling if you don’t know what you’re doing, and then the coffee will be under-extracted.

“So, you can end up with an amazing coffee and then… you do what you think to be exactly the same thing again and it just doesn’t deliver.”

And temperature instability, either due to the material of the pour over device, the size, the shape, or even the choice of pulse pouring over a continuous pour can also negatively affect the taste of your coffee. Ultimately, if the water cools too rapidly, it will change the rate of extraction.

“Pour over control is difficult,” says James. “There are many variables within it and having absolute control can be tricky.”

The elegant – but finicky – V60 pour over.

How does immersion brewing compare?

When it comes to immersion brewing, the key is in the name. The ground coffee is immersed in water and then left to brew until it is appropriately extracted and ready to be consumed. This means that rather than focusing on controlling the pour, brewers need to be thinking about the brew time.

With some immersive brewing methods, like cupping, the coffee grounds are left in the water. When cupping – which is how coffee quality is evaluated – this allows the drinker to taste the coffee at different levels of extraction.

In other immersion methods, the coffee grounds are filtered out. For example, with the French press or Barista & Co.’s Twist Press, this happens when the brewer presses or twists the device.

The Twist Press has two chambers: the main coffee chamber and a top chamber which forms a concentrated pocket of air above the brewing coffee when closed. Both chambers have their own separate handle. When the brewer is ready, they twist the two handles together. Corkscrew grooves on the sides of the main chamber use torsional force to produce an even downward pressure when the handles are twisted to meet, pushing the brewed coffee through a paper filter.

These immersion brewing devices add an additional factor to the brew method: it’s human pressure that forces the liquid coffee through the filter. In turn, this pressure can allow for a finer grind size and shorter brewing time.

Other immersion brewing methods allow gravity, rather than human pressure, to start the filtering process. The BrewThru Coffee Dripper, for example, resembles the traditional V-shaped funnel of most pour over devices. However, it has a valve located near the base of the funnel.

This valve allows users to control the steep time like a traditional immersion brew as well as the rate of flow when the valve is released. It may look like a pour over device, but it also borrows from the immersion brewing process.

The Twist Press with a freshly brewed cup of Blue Mountain coffee. Credit: Barista & Co

Why do we like immersion brewing so such?

Depending on the device, immersion brewing can be perceived as less fiddly than drip brewing. There is less need to monitor the process from start to finish, which is ideal if you prefer a simple brew method along with more easily achieved consistency.

Generally speaking, immersion brewing results in a bolder coffee profile with greater body. And for those who like the taste of immersion brewing but are less fond of the heavy mouthfeel, bypassing is an option.

This is the process of adding water to a concentrated brew; in essence, it dilutes the beverage. It’s the same process, in fact, as making an Americano.

James, for example, recommends bypassing a coffee concentrate as an option with the Twist Press, which he says produces “a very clean body… with rich texture and body”.

He feels that bypassing is intuitive even for most beginner brewers. “If you’re trying to introduce people into [the world of specialty coffee], confidence is generally a thing they don’t have,” he says. But bypassing is a forgiving method.

“We’ve actually found that using the bypass – or in layman’s terms, by diluting down the coffee – and reducing the TDS, even if you’re brewing for two people at home, for example… you can… get two really well-balanced, great cups of coffee out of it.”

Decanting freshly brewed French press coffee.

Challenges with immersion brewing

This brewing method has a less glamorous reputation than the pour over – but is it deserved? While not synonymous with immersion brewing, the most high-profile device is the French press, which works well with a coarse grind and subsequently longer contact time.

Unfortunately, many people over-extract their French press by failing to decant it immediately after plunging. However, it seems unfair to blame the device for our errors. Additionally, experimenting with a finer grind on the French press can also result in better extraction and flavour.

Some people consider immersion brewing to have too much mouthfeel. Most mainstream coffee presses are made with metal mesh filters between 80-300 microns. They don’t trap coffee oils and sediment as effectively, resulting in a heightened perception of the coffee’s bitterness.

“You can only use a certain micron level filter with a press, because it’s very difficult to plunge if it’s the wrong level. That’s certainly a negative with a standard immersion,” says James.

In addition, with French presses, it helps if you are not in a rush and have more time to spare for cleaning the device.

“When we’ve done research with consumers, we find that very few people use coffee presses during the week. It’s almost like they think they have more time in the weekend. ‘I’m going to sit and have a press coffee, read the paper,’ and then… often the coffee press gets left on the side unclean. I mean, we’re all guilty of it, you know.” James laughs. “I think there are certain negatives, just from a usability point of view.”

Finally, James argues that traditional presses with a downward pressure rather than a circular or sideways one result in less stability and consistency in the way we press our coffee.

“When you’re going in from side to side, it gives you stability. If you’ve got downward pressure on something, obviously you’re putting the pressure through the vessel as well as the product brewing, so… less stability,” he says.

A barista twists the Twist Press to force brewed coffee through the paper filter. Credit: Barista & Co

Different brew methods, different coffees?

Immersion vs drip coffee: one is known for its rich, bold taste and full body; the other for its cleanness, complexity, and highlighted acidity.

And then you have those brewing methods that borrow from both technologies, allowing for a clean cup with a bold taste, for example.

But does this mean that certain coffees pair better with certain brew methods? Should a high-acidity single origin always be brewed as a pour over, for example? Or is it simply a matter of personal preference?

“I think to say that there’s one type of coffee for any type of brewing method in my mind is wrong,” James tells me. “I think it’s more about you finding the one that’s right for you.”

Feature photo credit: Barista & Co

Please note: This article has been sponsored by Barista & Co. Their newest product, the Twist Press, is currently live on Kickstarter and can be backed here.

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The post Drip and immersion brewing: A battle of two methods appeared first on Perfect Daily Grind.

Yet somehow, today, the AeroPress is one of the world’s most iconic coffee-brewing methods; the tool of a world coffee championship, the World AeroPress Championship (W. A. C.); and even the subject of its own movie, AeroPress Movie.

How did this happen? We reached out to Alan Adler, AeroPress designer and President of AeroPress, Inc., to hear his opinion.

You might also like 5 AeroPress Lessons I Learned From 4 Champions – And Their Recipes

Brewing AeroPress coffee. Credit: Neil Soque

The Origins of The AeroPress

A small, two-tubed device, the AeroPress quickly brews a full-bodied coffee by allowing the user to push the water through the puck. Unlike pour over devices, it’s inspired by espresso machine technology – except electricity and levers are replaced by human pressure.

It also has similarities to the French press, although it’s become embraced by the specialty coffee industry in a way that the humble French press has yet to achieve. What’s more, the brew time (and recommended water temperature) is significantly shorter with the AeroPress.

In other words, while the device is a common sight nowadays, it was truly something out of the ordinary when it first appeared back in 2005. Alan Adler approached creating it like the engineer that he is, starting off with the problem (he wanted reduced bitterness in his daily coffee) and from there finding the solution (reduced brew time).

In order to reduce the brew time, he realised that he needed to take advantage of pressure. A closed chamber increased the pressure from the “push” sufficiently that Alan was then able to brew his coffee faster. (Of course, today, you’ll find a wide range of AeroPress recipes – some with longer brew times than others!)

Numerous prototypes later and Alan Adler had his AeroPress. His small, family-run business (which still only has a dozen or so employees) soon began producing it and demonstrating it at trade shows.

Alan Adler with an AeroPress Credit: AeroPress, Inc.

Winning Over The Coffee Industry

Many in the specialty coffee industry responded sceptically, dismissing the AeroPress as a gadget device from a toy maker rather than a revolutionary new brewer.

But over time, this started to change. Alan responded to the raised eyebrows with brewed coffee samples and the news began to spread. The proof of the AeroPress’ quality was, after all, in the coffee cup.

Yet there are many coffee brewing devices out there. How did the AeroPress achieve such remarkable popularity?

Alan says, “Coffee is a global phenomenon. And various brewing methods have gone global. It helped that the AeroPress brews a very tasty cup in one minute, is self-cleaning, portable, inexpensive and can be used many different ways.”

And maybe there was something else behind the AeroPress’ surge in popularity – the very same thing, perhaps, that led to the World AeroPress Championship. I’m talking about the ability to experiment.

Brew time, push time, coffee dose, coffee:water ratio, water temperature, and even whether or not you invert the brewer; there is a wealth of ways to play with the AeroPress and so enhance different characteristics in your brewed coffee.

Discover more in: AeroPress Coffee Guide: How to Brew For Different Flavor Profiles

Ready to brew: ground coffee inside an Aeropress. Credit: Fernando Pocasangre

Champion of The World

Specialty coffee has plenty of competitions: the World Barista Championship, the World Brewers Cup Championship, the World Latte Art Championship, the World Roasting Championship… not to mention all of the green bean competitions and awards.

But in 2008, a new one appeared – an irreverent, playful one that never expected to be taken seriously. The first ever World AeroPress Championship (W.A.C.) was held in Oslo and, despite the grand name, had just three competitors. It was organised by Tim Varney (who still runs the event today, along with Tim Williams) and Tim Wendelboe.

But – much like the AeroPress itself – the competition has become a popular and indispensable part of the coffee championship calendar. In 2018, over 3,157 people from 61 countries competed, watched by a grand total of 68,265 eager spectators.

“Obviously, an AeroPress can be used many ways. Competitors invent new ways and fine-tune existing ways. It’s not likely that a competition could develop around a push-button automatic brewer,” says Alan.

He considers the W.A.C. to be “the people’s championship”, one that anyone can compete in, regardless of their resources or access to green coffee. It’s one that rewards creativity and experimentation – so long, of course, as that creativity results in better coffee.

You might also like: How Have World AeroPress Championship Recipes Changed Over The Years?

Brewing AeroPress coffee with the inverted method. Credit: Fernando Pocasangre

What’s Next For The AeroPress?

The AeroPress has gone from underdog to a giant of the coffee industry. Yet while its success has rocketed, little about the device has changed. It’s now a transparent black as opposed to clear plastic, but if it weren’t for that, you would be hard-pressed to spot the differences between one from 2006 and one from 2019.

Yet is something new on the horizon? “A more portable version is coming soon,” hints Alan, while not giving any further details.

As for the W.A.C., Alan is optimistic about its future growth. “We strive to enhance the enjoyment of the participants. That’s our highest priority. This year’s event was extended from one day to two days and the participants all loved the opportunity to socialise. More enjoyment will be added in 2019,” he says.

Enjoyed this? Check out 5 AeroPress Lessons I Learned From 4 Champions – And Their Recipes

Feature photo credit: Camilo Marulanda.

Please note: This article has been sponsored by AeroPress, Inc.  

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The post The History of The AeroPress, From Concept to Championships appeared first on Perfect Daily Grind.

Let’s find out more about how the geometry of a batch brewer basket or pour over filter holder can influence your daily cup.

You May Also Like Everything You Need to Know to Brew Great Pour Over Coffee

The Kalita Wave has a flat-bottomed base. Credit: Thomas Martinsen

Investigating The Impact of Basket Shape

Professor William Ristenpart is the director of UC Davis Coffee Center, where he researches ways to brew better filter coffee. He tells me that most commercially available brewers have either a flat-bottomed or semi-conical basket.

“Roughly speaking, half of them are flat-bottomed and about half are semi-conical,” he says. “However, what’s kind of been missing is any hard data to support any type of analysis of which is better. One of the questions we ask is: should we compare brew ratios for flat-bottomed versus semi-conical?”

But how do we determine which makes a better brew? It’s difficult to evaluate and compare quality. The Specialty Coffee Association (SCA) offers a Brewing Control Chart, which Ristenpart tells me he uses to help evaluate brew profiles. But he notes that this measure isn’t without its flaws.

“What is the difference, if any, in sensory properties of drip coffee when you use either a flat-bottomed or semi-conical filter basket? We put together a whole bunch of sensory tests to try to answer the question. The basic idea is to use everything the same: same coffee, same grind size, same water temperature, same everything, except for the basket geometry,” says Ristenpart.

His team found that basket shape does make a difference. “In terms of our sensory evaluation, basket shape made maybe even a more pronounced impact than the grind size did,” he says.

A Behmor Connected batch brewer. Credit: Behmor

Why Basket Shape Matters

Brewing coffee is essentially a controlled exercise in chemical changes. When we make a cup of coffee, we’re encouraging molecules to move from the coffee solids into the water.

“The nature of the fluid flow through the porous media (the coffee grounds) is influenced by the shape of its container (the basket). The container affects the degree of mass transfer that occurs. In other words, it affects how much extraction occurs,” Ristenpart says.

“If you have a flat-bottomed basket, water’s hitting it in the middle, spreading out radially, and then exiting through a hole or multiple holes also in the middle. That flow pattern is different if you have a semi-conical shape where it’s hitting it in the middle. It doesn’t spread out as much radially,” he says.

Learn more in Understanding Coffee Extraction For Your Perfect Cup

Behmor’s ground basket. Credit: Behmor

Of course, there are many ways that baristas modify the flow of water to impact the final profile of your coffee. When making a pour over, there are different pouring techniques including the circular pour, single pour, pulse pouring, and many others. SCA-approved batch brewers focus on distributing water evenly across the bed of coffee grounds to promote even extraction and limited temperature fluctuation.

The Coffee Center’s research shows that there are differences in profile between coffee made in a flat-bottomed basket and a conical one, and suggests that this is caused by the different ways water flows through the bed of coffee. But it’s possible to modify the water flow and therefore the final brew in either basket shape by changing the pouring technique.

Learn more in The Specialty Coffee Shops That Prefer Batch Brewers to a V60

A barista makes a pour over coffee. Credit: Jakub Kapusnak

Which Basket Shape Is Best?

So, which basket shape should you use? Like many things in coffee, it’s a matter of personal preference.

“When we had our expert panel do a sensory descriptive analysis of identical coffees, but brewed with either the flat-bottomed or conical, the panel pulled out very different flavor profiles. They noted more tea/floral-like flavors in coffee made using conical baskets and more smoky, tobacco-y, roasty flavors with the flat-bottomed,” Ristenpart says.

But he warns against overstating the importance of basket shape.“The first thing that controls the flavor is the quality of the beans themselves,” he says. “I don’t want you to come away thinking that the conical is always going to get more tea-like, floral flavors. That’s not true because it really depends on the type of coffee that was used in the first place.”

The Behmor Brazen batch brewer. Credit: Behmor

Making a good cup of coffee is a balance of many related variables. Your choice of basket shape may not be the most important factor in determining a coffee’s profile, but the evidence suggests that it does play a role.

So if you’re in the market for a new pour over device or batch brewer, or are unsure of what method to order at your local specialty coffee shop, keep basket shape in mind when making your choice.

Enjoyed this? Check out Coffee Science: Breaking Down Where Flavour Comes From

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The post Can Filter Basket Shape Affect The Flavor of Your Coffee? appeared first on Perfect Daily Grind.