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What is Air Roasted Coffee?
Discover what is air roasted coffee and its differences with other types of coffee.
Published February 8, 2022
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Yker Valerio
Coffee experts@The Coffee Lab
Curious about air-roasted coffee? Then, I wrote this article for you.
Coffee roasting has become increasingly popular among enthusiasts. Many are starting a hobby roasting coffee at home, something that was a common choir a few hundred years ago.
Currently, home coffee roasters come at all shapes, sizes, and prices, and air coffee roasting is an affordable way to start. However, commercial-grade coffee roasters are a lot more expensive and sophisticated.
In any case, the basics are similar. Air roasted coffee is different from other types of coffee, and you can find more details below.
What is Air Roasted Coffee?
Roasting is a culinary process, as many experts claim. It’s crucial to understand that coffee roasting is a sophisticated cooking process. Grasping this seemingly simple concept helps avoid unnecessary complications.
Simply put, air-roasted coffee is the result of a convection process. The difference between roasting and baking is that the latter doesn’t require as much movement as roasting.
Movement is essential for obtaining even roasts, and fluid bed roasters -or hot-air roasters- use hot air streams for tumbling coffee beans during the roasting process.
The Air Roasting Process
Many popcorn makers use a similar process to air roasting. Using a limited space for efficiency, an air roaster has a heat source and a ventilation system to distribute hot air inside a chamber.
The most advanced roasters can measure coffee beans’ temperature during the process. Measuring the coffee beans’ temperature is crucial for roasting because it helps formulate recipes. Additionally, the temperature is more reliable and accurate than color when assessing the development of the process.
One of the most fascinating aspects of air roasting is obtaining a more reproducible and consistent result. Particularly when monitoring temperature curves. The hot air tumbles coffee beans during roasting, helping to distribute the heat around them evenly.
But, do you know which are the types of coffee roasters?
Types of coffee roasters
Most experts classify coffee roasters into drum roasters and fluid bed roasters. However, I found a couple more inside James Hoffmann’s World Atlas of Coffee. You can read below a short description of each type of coffee roaster that I found.
Drum roasters
It’s a rotating metallic drum that spins over a flame. The coffee beans movement aims to get even roasts. These are the most conventional and widely used coffee roasters.
Air or fluid bed roasters
Michael Sivetz invented the fluid bed roaster in the 1970s, looking to solve the problems caused by drum roasters. They tumble and heat beans using hot air jets. A fan distributes a continuous and uniform flow of hot air. Although many people consider that they’re technically superior, they haven’t increased the popularity of traditional drum roasters.
Tangential roasters
Many people consider tangential roasters a type of drum roaster. However, they are different from drum roasters because they have internal shovels that mix the coffee beans during the heating process. Through this technology, tangential roasters achieve superior results in large batches.
Centrifugal roasters
Using an inverted cone, this type of roaster spins coffee beans to draw them to the walls during the roasting. In intervals, the coffee beans go back to the center of the cone, and this process goes back and forth several times.
According to James Hoffmann, these roasters can produce a tremendous amount of coffee in a shorter time, although compromising quality.
Air Roasting vs. Drum Roasting
If you place green coffee beans on a baking sheet, you’ll obtain an uneven result. The same happens if you try to roast coffee beans using a pan and you can’t manage to stir them quickly enough.
To some extent, heat transfer between coffee beans is as essential as that occurring between the beans and the drum. For this reason, drum roasters move the coffee beans to obtain a more uniform result. However, compared with the air roaster, the drum roaster is less consistent.
Another difference between air roasting and drum roasting is chaff -or silverskin- management. The chaff burns inside drum roasters, affecting the taste and aroma of coffee beans. Air roasters have a unique technology to deal with the silverskin, which services it without burning it.
Finally, a crucial difference between both systems is the roasting time. Drum roasters usually take more than twelve minutes to roast a batch, while air roasters take an average of five minutes.
While centrifugal roasters are the fastest to manage large batches, they compromise quality. In this regard, air roasters work quicker, without affecting the result. Arguably, air roasting enthusiasts claim that the results are superior to drum roasting.
In short, air roasting and drum roasting mostly differ in:
- Roasting uniformity
- Chaff management
- Roasting time
Benefits of Air Roasting
Considering the differences, we explained above, the benefits of air roasting are easier to understand.
First, as air roasting is faster, it can lead to more efficiency without compromising the quality of the final product. In this regard, to assure quality, it’s vital to use monitoring systems that aren’t built-in in most fluid bed roasters.
Additionally, air roasting is cleaner because it disposes of silverskin in an organized manner. Moreover, as the heating process occurs through air streams, it’s more consistent because coffee beans transfer energy between them without getting in touch with scorching surfaces like drum roasting.
Simple hot air coffee roasters can be hard to handle, and it’s pretty challenging to accomplish a decent medium or light roast with cheap air roasting gear. On the other hand, maintenance and cleaning of air roasters tend to be more accessible. Furthermore, many home roasters and professional roasters agree on the usability advantages of air roasting equipment. The latter is particularly true with more advanced gear.
Final thoughts
In our consumer role, we don’t get the chance to know what type of roaster is using our favorite brands. Perhaps the best shot we have is to buy from small roasters and ask them directly.
If you have the opportunity to try different roasts at home, give it a shot. Then tell us what’s your favorite. Do you love air-roasted coffee? Or you’re more inclined to drink drum roasted coffee?
Let us know in the comments below!
Frequently asked questions about coffee roasting
Coffee roasting has evolved dramatically in the past few decades. A science-based roasting approach and more advanced technology have led to many coffee aroma and taste changes.
Bear in mind that roasting is just a variable, though. Coffee processing methods and coffee varieties also play a considerable role in coffee taste and aroma.
Without further ado, let’s focus on some common questions related to coffee roasting.
What are green coffee beans?
We tend to refer to roasted coffee seeds like coffee beans. Some may claim is inaccurate, but tradition has been quite strong.
Green coffee beans usually refer to coffee seeds obtained after processing coffee berries to remove the fruit skin and pulp.
Roasted coffee beans acquire their typical color through the well-known Maillard reaction. In darker roasts, sugars in the coffee seeds caramelize and even burn, providing the distinctive taste and mouthfeel of darker roasts, like the French roast.
Which are the types of coffee roasts?
The easiest way to classify coffee roasts is to separate light, medium, and dark roasts. You can find certain degrees between these roast types, but the differences in taste, aroma, and body are evident between the three.
Some other roasts were popular such as Vienna, French, Italian, or City. However, it’s easier to discern between light, medium, and dark. Differences between dark roasts like French and Italian can be pretty arbitrary depending on the roaster. Commercial brands that offer low-quality coffee beans are more inclined to offer these old-school classifications.
In this regard, although the coffee quality isn’t a black or white thing, I prefer to acquire coffee beans classified using dark, medium, and light, with information about the origin, roast date, and processing methods.
The more effort companies put into transparency and traceability, the higher are the chances that coffee beans are of high quality.
How should I store coffee beans?
Roasted coffee beans need to degas before getting at their best aromatic profile. Storing freshly roasted beans requires to use of special containers and bags that help to release carbon dioxide.
After degassing, it’s better to keep coffee beans in airtight containers, away from the sunlight. Remember that oxygen and UV rays accelerate coffee deterioration, negatively affecting its aroma by decomposing oils, fibers, and aromatic compounds in coffee.
About the author
Yker Valerio
Yker Valerio (he/him) is a freelance content creator. After more than 10 years of working as a management consultant, he started his blog Bon Vivant Caffè to share his passion for specialty coffee.
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