Understanding the Process: Anaerobic Processing

Understanding the Process: Anaerobic Processing

Understanding the Process: Anaerobic Processing

Get Ready for The Barista League’s 2024 Season

The Barista League has announced 12 competitions across four continents. BY J. MARIE CARLANBARISTA MAGAZINE ONLINE Photos courtesy of The Barista League When The Barista League announces new events, it’s worth paying attention! This year, the schedule will be organized by geographic location, bringing together coffee people in various communities. At The Barista League in […]


Brewing at Home and on the Road with Wilford Lamastus Jr.

We talk to the multi-time Panama Brewers Cup champion about his brewing preferences. BY TANYA NANETTISENIOR ONLINE CORRESPONDENT Photos courtesy of Wilford Lamastus Coffee professionals tend to spend most of their days brewing coffee. It can be an espresso shot pulled for a customer or a cupping to check out a new roaster to choose […]


U.S. Coffee Championships 2023 Baltimore Qualifiers Results

More than 100 competitors brought their talent to Baltimore to take part in six competitions, and 63 will progress to nationals in April. BY NATE KLOCKBARISTA MAGAZINE ONLINE Photos by Matthew Temple courtesy of the U.S. Coffee Championships Last weekend, my hometown welcomed the U.S. Coffee Championships (USCC) qualifiers with the charm only Baltimore could […]


How to roast anaerobically fermented coffee

Among the many different kinds of experimental processing methods, anaerobic fermentation is perhaps the most popular and intriguing. Interest in this processing technique is only growing, with more and more anaerobic fermented coffee available in cafés and roasteries around the world. Moreover, of all the advanced processing methods, this particular technique has one of the […]

Understanding the Process: Anaerobic Processing

What are modular espresso machines & how do they work?

For decades, espresso machine design and technology have been evolving to meet the ever-changing needs of coffee shop owners and baristas. From multi-boiler systems and automation to custom branding, there are now more factors to consider than ever before when it comes to the design of an espresso machine. Many businesses choose to position their […]


Breaking New Ground: A Sicilian Coffee Plantation, Part One

The impacts of climate change are starting to be felt in Sicily, but while they’re causing problems, the rising temperatures are also bringing new opportunities. BY JOSEPH PHELANSPECIAL TO BARISTA MAGAZINE ONLINE Featured image courtesy of Henrique Ferreira on Unsplash The Sicilian love affair with coffee is known the world over. Sicily, the largest of […]


3 Noteworthy Cafés in the Borough of Brooklyn, N.Y.

We explore three standout Brooklyn cafés: drip, BKG, and Coffee Project New York. BY EMILY MENESES BARISTA MAGAZINE ONLINE Cover photo by Nelson Ndongala via Unsplash Whether you’re a New York local or planning your next NYC trip, you won’t want to miss out on Brooklyn’s vibrant (and constantly evolving) coffee scene. Today, we’re exploring […]


Study Shines New Light on the Complex Arabica Coffee Genome

Researchers in Italy say they’ve shed new light on arabica coffee’s large and complex genome, which may ultimately help breeders seeking desirable traits such as high quality and disease resistance….

Understanding the Process: Anaerobic Processing

Understanding the Process: Anaerobic Processing

minimum dose size?

I use the Hario switch to brew my coffee and am trying to reduce my caffeine consumption. Hence I would like to brew smaller cups of coffee. I am currently using 10g of coffee with 160g of water. (1:16 Ratio) I am wondering if there is a minimum amount of coffee...

Understanding the Process: Anaerobic Processing

We continue our series on fermentation with a look at the anaerobic process, which has quickly become a favorite in cafés worldwide.

BY TANYA NANETTI
SENIOR ONLINE CORRESPONDENT

Photos courtesy of Bram de Hoog for Ally Coffee

A simple cup of well-brewed coffee can have endless variations of flavors and aromas. These are closely linked to the many chemical aspects of the coffee itself. Origin, varieties, fermentation, and roasting style also deeply influence the final cup, so it’s worth understanding these variables better. Today, we’ll take a look at a newer type of coffee processing that has already become an instant classic: anaerobic.

A square shaped metal vat holds raw coffee cherries in orange red tones before they are to be sorted and processed. The batch is so fresh it still has coffee leaves mixed in.
In anaerobic fermentation, cherries are typically whole but may also be pulped before the fermentation process.

Bram de Hoog, specialty coffee sourcing manager at Ally Coffee, is originally from The Netherlands. He found his way into green coffee and worked for five years in Central America (in Nicaragua and Costa Rica) before moving to Germany. He often travels to visit Ally’s partners and producers around the world, and he shared with us some of his thoughts on the anaerobic process.

The Anaerobic Process

“Anaerobic processing is a style of fermentation that happens without the presence of oxygen. This can be for natural, honey, or washed coffee,” Bram explains. “Coffee, usually in cherry form (but it can also be pulped), is placed in barrels that are sealed off from the outside air. There’s a one-way valve on top of the barrel which allows oxygen to be pushed out. Fermentation releases gasses which push the oxygen out through this valve, creating an anaerobic environment over time.”

As for the typical flavor profiles of anaerobic processed coffees? “A wide range of flavor profiles exist: This also obviously depends on the type of anaerobic process used—washed, honey or natural,” Bram says. ”However, in general, one could say anaerobic-processed coffee has a heavy body, and a winey/rum and raisin-like flavor, in addition to tropical fruit and notes of fermented cacao.” 

A man's hands hold up a mound of sludgy coffee cherries after being held in a round vat. The liquid in the vat is viscous and pink.The cherrues have lost much of their color to the liquid.
Anaerobic coffees typically have a heavy body, winey/raisin flavors, and fermented cacao notes.

Positives and Negatives

Like any other fermentation, anaerobic processing also has both pros and cons. “It can drastically increase a coffee’s cup score and hence the value of the coffee,” Bram says. Furthermore, the anaerobic process, when compared to other types of fermentation, can give producers better control of the fermented batch. Once the right profile has been found for a coffee, no outside factors (temperature, rain, air quality, etc.) precludes the possibility of repeating the exact same process for the following batches.  

On the other hand, Bram adds that this type of fermentation “has a steep learning curve, and any mistake can ruin a batch of coffee.” 

Moreover, it should be remembered that anaerobic fermentation is more expensive than the more traditional types of coffee processing (natural, washed, and honey). Anaerobic fermentation requires special sealed tanks to be used during the fermentation; these must then be regularly monitored for accurate control of the processed batches, so it requires additional manpower. Hence, this is not a process that all producers can afford. 

An outside view of a large metal barrel for coffee fermentation. It is tall, held upright by a yellow stand with an A frame and 4 legs. At the top is a large hole for dispensing and a small valve for releasing gases as the cherries ferment.
In anaerobic fermentation, cherries are sealed off from outside air, limiting the potential for environmental pollutants.

The Future of Anaerobic Processing

Finally, Bram shares a few words about how the anaerobic process is evolving. 

“As the process becomes more widespread,” he concludes, “there are more and more sub-variations of anaerobic. It should also be emphasized that the pioneers of this process were very meticulous in developing their recipes; some newer producers, on the other hand, may not be as careful with their processing.” 

As coffee fermentation evolves over time, there will be more experimentation with the anaerobic process. For now, its popularity is continually increasing.

ABOUT THE AUTHOR

Tanya Nanetti (she/her) is a specialty-coffee barista, a traveler, and a dreamer. When she’s not behind the coffee machine (or visiting some hidden corner of the world), she’s busy writing for Coffee Insurrection, a website about specialty coffee that she’s creating along with her boyfriend.

The post Understanding the Process: Anaerobic Processing appeared first on Barista Magazine Online.

Shopping cart0
There are no products in the cart!
Continue shopping
0