What is Fermented Coffee?


Ever heard of fermented coffee beans? Discover all right here!


Fermented Coffee: what is this new coffee trend?

Potty about pickles? Krazy for kombucha and kimchi? And don’t forget the kefir (why do they all begin with k??)!

We all know fermentation is on trend. And guess what? This buzzword has arrived with ‘da beans! That’s right; over the past decade we’ve seen rising interest in coffee fermentation.

So, is it worth it? Or do fermented coffee beans taste like gherkins? Let’s find out!



What is Fermented Coffee?

Fermented coffee, also known as cultured coffee, describes coffee that has undergone carefully controlled fermentation.

Now, this is where it gets a bit confusing, because almost every roasted coffee bean you see will have enjoyed a spot of fermentation at the processing stage. More on this in a bit (we’re good at this suspense stuff, right?)

Fermented coffees, however, are different. The fermentation is an additional, very deliberate stage that takes place after the processing. It’s an extra, an add-on, a star in its own right rather than part of a process.

Why bother? Fermentation can bring lots of cool new flavours to a coffee, plus some rather sassy health benefits. Again, more on that coming up. You are literally on the edge of your seat right now, aren’t you? Thought so.


What makes fermented coffee different?




What is Fermentation?

Fermentation is a natural chemical reaction that’s the cornerstone of many of our favourite foods. Like a glass of wine or some cheese after your dinner? Neither would exist without fermentation.

In super-simple terms, fermentation converts some of the components in a food into other compounds.

In slightly more specific terms, it’s when yeast, bacteria and other microorganisms cause sugar and starches to break down into nutrients plus other compounds like alcohol and carbon dioxide. We’ve used fermentation for yonks to preserve foods the natural way (no artificial preservatives in 7,000 BCE, you see) and improve their flavour.


Speciality coffee processing in Brazil




How is Fermented Coffee different from Regular Coffee?

If you’ve checked out our guides to coffee processing, you’ll know that fermentation is not a newbie in the coffee world: it’s important in most coffee processing methods.

Farmers process their coffee cherries to remove the beans from the fruity layers surrounding them. In the natural process, farmers leave their cherries to dry on tables or patios for several weeks, and a little fermentation starts a-going-on at this stage.


Natural process coffee beans resting on raised beds


Washed coffee, meanwhile, describes coffee processed using water. The cherries enjoy a bath in flotation tanks, and the fermentation that happens in the tank breaks down the cherries’ fruity mucilage layer.




So, yes, fermentation is important to all coffee. But it’s not the star in all coffee. It’s just a very useful part of a process. With fermented coffees, meanwhile, the fermentation is scrupulously controlled to create tantalizing new flavours. The fermentation takes place after the coffee processing stage – it’s a bonus extra!




Fermented Coffee Process

Here’s a peek at one of the most common coffee fermentation methods:

  1. Coffee producers start with green (unroasted) coffee beans.
  2. These beans have already been processed. They can be washed or natural-processed coffees.
  3. Next, they soak the beans in water.
  4. Now add the magic ingredients! The producers combine the coffee beans with bacteria and yeast before leaving them to rest for one/two days. The beans don’t get much privacy, though – it’s important to monitor the fermentation conditions VERY carefully.
  5. The fermented coffee beans then need to be washed and dried before roasting. Then they’re ready for your mug!


Graph showing the process of coffee fermentation



There are also some quirkier coffee fermentation methods out there…



Barrel Aged Coffee

Boozy beans are a thing! Here, green coffee gets tipsy as producers age it in freshly emptied barrels previously used to make distilled liquors like whiskey or gin. The beans soak up hints and undertones of the previous process and take on eccentrically awesome new flavours!

Fancy whisky barrel-aged coffee (the most common type of barrel-aged coffee)? Get ready for a robust, heady brew. Want something sweeter with harmonious balance? Go for coffee beans aged in run barrels.


Types of barrel aged coffee




Fruit Fermentation

T Total or like getting your five-a-day*? Try coffee fermented with fruit! In this peachy process, coffee and fruit get sealed together in a dark, stuffy space… Ooooh naughty!

You can find coffees fermented with a range of fruit bowl friends – grapes, oranges, lemons, passion fruit! It’s a fruity frolic! 🍇🍊🍋

*Fruit fermented coffees don’t actually count as one of your five-a-day. Soz.


Types of fruit fermentation coffee





What Does Fermented Coffee Taste Like?

The type of bean you pick, plus your brew method of choice, will still play a super-duper important part in your coffee’s final flavour.

However, go for a fermented coffee and you’ll likely experience something a bit out there.

‘Hmmm,’ you’ll ponder, ‘this coffee tastes a little different. Not weird, certainly not, just deliciously different!’

Try fermented coffee beans, and we bet your bottom dollar that you find:

  • Complex layers of flavour
  • A lush natural sweetness (providing you brew correctly!)


Freshly roasted coffee in an orange coffee mug



Are Fermented Coffee Beans Healthier?

Doctors love their fermented foods, don’t they? It’s all down to their probiotics – the gut-friendly kind of bacteria. Fermented coffee beans aren’t a good source of probiotics, however. Well, they would be if you ate them raw, but we wouldn’t recommend that (raw coffee isn’t exactly delicious…). Roasting caramelises the lovely natural sugars in green beans and brings out the coffee flavour, but it does quash the probiotics in the process.

So should we not roast? Nahhh, we’ll pass on the raw coffee drinking, thanks. It tastes like grass…

BUT, THERE’S GOOD NEWS. There are more fermented coffee benefits!

  • Easier to digest: because tricky-to-digest substances are ‘pre-digested’ in the fermentation process, making fermented coffee beans easy on your tum
  • Less tannins: tannins are a type of natural polyphenol that promote teeth staining. Fermented coffee contains just a few of them, keeping your pearly whites… white!


Coffee cherries in white sacks


Oh, and don’t forget coffee – fermented or not – is a powerhouse of health benefits!

Do you fancy making your healthiest ever coffee at home? Check out this essential guide!


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Charlotte Dibble

Meet the chimp behind this article!
Charlotte joined Two Chimps after completing her BA Hons in Graphic Communication and Illustration at Loughborough University. She also earned two diplomas: Art and Design Foundation and Professional Studies.

What Charlotte does outside of the treehouse:
In her spare time, Charlotte is a keen baker and loves to bring delicious treats for the team to enjoy during their Monday tea break. Charlotte likes to practice her drawing and painting skills to relax, usually with one of her cats sitting on her lap to keep her company!

Charlotte says…
“I’m thrilled to join the Two Chimps Troop after five years of studying. I get to write blogs, design, manage social media, and connect with our amazing customers every day. It’s always exciting, and I learn something new every day!”

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