What is Fermented Coffee? – Types, Benefits & Process

Fermented coffee is a cup of coffee that has been brewed using fermented beans. The short answer is always out of the way, and time for more details. Fermented coffee has high popularity for multiple …

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Fermented coffee is a cup of coffee that has been brewed using fermented beans.

The short answer is always out of the way, and time for more details. Fermented coffee has high popularity for multiple reasons:

  • Unique flavor profile
  • Unique Aroma
  • Health benefits
  • Extended shelf life

So today, let’s talk all about fermented coffee and the fermentation process of coffee. And of course, you can prepare fermented coffee at home as well.

What is Fermentation?

Fermented Coffee Beans

Fermentation is a biological process that takes place naturally. Fermentation occurs when different bacteria and yeasts gather on an environmental element and start breaking down the starch and sugar content present to collect nutrients to survive.

While they keep breaking down the components into enzymes, a wide array of byproducts get released as a result, which are:

  • Organic acids (like acetic acid)
  • Different alcohol types (like ethanol)
  • Different gasses (like carbon dioxide)

Fermented coffee, also known as cultured coffee, is coffee beans fermented after being pulped and the husk is removed.

When you roast, ground, and brew fermented coffee, you can tell that fermented coffee has an entirely different aroma.

Another type of coffee is fermented after the brewing process is complete. This process can be time-consuming since it takes several days for the coffee to be wholly fermented and reach a drinkable state.

A famous example of coffee that is fermented after brewing is Kombucha. Kombucha is fermented after it’s brewed via a highly concentrated process, which we’ll discuss later.

Types of Fermentation

Fermentation is a vital part of post-harvest coffee processing. It can happen in one of two ways:

Aerobic Fermentation

Aerobic fermentation mainly occurs in natural coffee beans. Whenever oxygen is available, aerobic fermentation can take place.

For aerobic fermentation, coffee farmers pick the cherries from plants and lay them out in the sun. The degree of fermentation depends on the temperature the cherries are drying in, and the time it takes to lose all the moisture content.

Suppose the cherries are dried out in the full sun. In that case, they’ll actually be less fermented since the coffee cherries will be thoroughly dried before the proper fermentation process can take place.

The farmers have to keep the coffee fruit partially in the shade to get the most out of the anaerobic fermentation process. Hence, the fermentation process has enough time to take off.

Anaerobic Fermentation

Anaerobic fermentation is the exact opposite process of the earlier one. Anaerobic fermentation occurs in sealed stainless steel fermentation tanks full of either carbon dioxide or water.

A great example of anaerobic fermentation is the carbon maceration process.

After harvesting the coffee cherries, coffee farmers throw them in a stainless steel tank that is completely sealed. They then pump the tank full of either carbon dioxide or water.

The oxygen trapped in the tank gets pushed out by the carbon dioxide via a valve on the top since oxygen is lighter than CO2.

In the sealed water tank, the bacteria have all the time in the world to create the coffee we love.

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How Does Fermentation Affect Coffee Quality?

The coffee fermentation process is highly complicated, making or breaking the coffee’s entire flavor profile. Therefore, the fermentation process must be closely observed; otherwise, it creates terrible results.

If the fermentation process is entirely uncontrolled, the result can be moldy coffee or coffee that tastes like a bunch of chemicals thrown in the cup from your college science lab.

To ensure enhanced flavors in coffee, the producer of the fermented coffee has to thoroughly understand the process, monitor it firsthand, and apply the best practices.

Here are a few ways how fermentation affects the coffee structure:

  • Refines the taste
  • Can create specialty/ exotic coffee
  • Adds distinguished fruity and chocolate flavor notes to the coffee
  • Emphasizes clean acidity and the aroma
  • Dismisses some astringency

Consistency & Fermentation: Do They Get Along?

When you’re thinking about great coffee, it isn’t just coffee that was great only once or twice. Instead, great coffee means coffee that consistently offers a high-quality taste and coffee experience.

Though this can be a hit and miss with fermented coffee, fermented coffee manufacturers are trying to stabilize the process to improve the rate of repeatability.

The first and most important way to ensure repeatability of the process outcome is to understand the process itself. When the staff related to the process are adequately trained on different quality analysis processes, like coffee cupping, the manufacturer can evaluate the experiment’s effectiveness.

When you know something by heart, you can repeat the same process over and over again.

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Only this time, the results will actually be something that the manufacturers can provide to their customers confidently and is a good product for export.

Let’s not forget about keeping it all tidy. Clean equipment can always make things better. When you’re sure your equipment doesn’t have excess chemical equipment present in there, you can hope for better results.

An obvious yet vital step is to record every step of the fermentation process. That way, when the fermentation yields a perfect result, the recorded data can be used to repeat the perfection.

The entire process of fermentation is something that we cannot stop. But the best we can do is either let it happen in a controlled form with technical steps or embrace it as it is.

Hey, Havin fun? You’ll love to read our piece on brown sugar in coffee.

How Is Fermented Coffee Made?

Here are the detailed steps of how fermented coffee manufacturers go through the whole process:

Step #1: Soak

The farmers soak the green beans in water. Doing so makes it easier for the microorganisms to make contact with the bean and gradually start growing in the said bean.

Step #2: Inoculate

Think about sowing seeds, but in this case, you’re throwing a handful of bacteria and yeasts in the soaked coffee beans.

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Don’t worry; they aren’t exactly thrown in by the handful. Instead, they’re introduced to the soaked coffee beans via a liquid form, known as a “starter solution,” as it starts the fermentation process.

Different starter solutions can produce different flavor profiles and aromas. You know how different cheese types are aged with different microorganisms, right? It’s just like that.

Step #3: Wait

For the bacteria to properly ferment the coffee, the farmers have to leave the coffee beans soaked in bacteria-filled water for 24-48 hours.

During this time, the bacteria and yeasts introduced in the mixture via the starter solution start working their magic, which changes the entire chemical composition of the green coffee beans.

This step may sound like it’s effortless since you just need to wait, but it’s actually the most complicated part. Changing different small factors of the fermentation can allow you control over the entire process. These factors include:

  • Temperature
  • Air exposure
  • Light exposure
  • Time of fermentation

Unless you’re an expert, this is the part where your entire process can get totally ruined. For example, if you wait too long or turn the temperature too high, your coffee will taste like vinegar.

Many manufacturers get this part right via trial and error. In contrast, some others take a more scientific approach to it all.

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Step #4: Wash & Dry

Now that the beans are fermented, it’s time to rewash them to clean off the residues from the process. Then the beans are dried before roasting. If not dried completely, the beans might get fermented further or spoiled in the storage.

Step #5: Roast

When the fermented beans are being roasted, the organic compounds inside the bean get oxidized by the roasting process. As a result, the roasting method affects the overall taste of the beans. That’s why this is another step where the roaster has to keep a keen eye on the whole thing.

Step #6: Grind

You can either buy whole fermented beans or buy pre-ground fermented coffee beans that are compatible with most coffee makers out there.

If you choose to buy the whole beans, you can enjoy the aromatic process of grinding whole coffee beans.

Having fun Nomies? Check our piece on what is nitro (nitrogen infused) coffee.

Benefits of Fermented Coffee

Fermented coffee is trendy, just not because it’s cool to drink coffee that has been processed with bacteria. But, ironically, this coffee has many more healthy properties than regular coffee.

It’s normal to think that fermented coffee is full of probiotics since it’s, well, fermented.

The fermentation process occurs before roasting, and the roasting gets rid of all the present probiotics from the coffee.

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But nothing to worry about. There are still 5 more benefits to fermented coffee.

Benefit #1: It’s Much Easier To Digest

When the fermentation occurs, the bacterias transform the hard-to-digest substances into easier-to-digest, simpler molecules. And obviously, that makes it easy to digest this coffee than regular coffee.

Benefit #2: Easier on IBS patients

If you are an IBS (Irritable Bowel Syndrome) patient, you may have been staying away from coffee for a really long time. But, gladly, you can quickly drink fermented coffee since it barely irritates your stomach.

Benefit #3: Cleaner and safer

The microorganism that causes the fermentation process improves the growth and appearance of fungi in the beans. That way, the beans last longer without getting spoiled. And of course, your drinking experience is now much cleaner, smoother and safer.

Benefit #4: Improved taste and aroma

As we already mentioned, fermentation changes the entire composition of the coffee bean and enhances overall flavors.

Fermented coffee is also less bitter than most regular coffee if that isn’t enough. And suddenly, you realize you can have a richer coffee experience.

Benefit #5: Fewer Tannins

Tannin is an element that turns your teeth yellow when it comes in contact with your teeth. It is regularly found in tea, coffee, wine, and other foods.

When you drink fermented coffee, you don’t have to fear the tannins making you look like a pirate in the 1800s with zero dental facilities whenever you smile.

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How To Make Fermented Coffee At Home?

Though the fermentation process is pretty easy at home, you need proper equipment and the required knowledge to monitor the whole process.

But I believe in you. You got this.


  • Brewed coffee
  • Sugar
  • Kombucha SCOBY
  • Glass Jar
  • 3-5 days of time
  • Lots of patience


  • Put the sugar and brewed coffee in a glass jar
  • Stir the mix till the sugar is completely dissolved
  • Allow the mixture to cool down
  • Add the Kombucha to the jar and cover it with a cheesecloth or a paper coffee filter.
  • Use a rubber band to secure the covering on top of the jar
  • Let the jar sit at room temperature for up to 5 days, but keep it away from direct sunlight
  • Remember to check for signs of rancidity everyday
  • Once you feel like your favorite taste is there, remove the SCOBY, and store the coffee in the fridge.

Can Brewed Fermented Coffee Go Bad?

If you brew and then ferment your coffee with coffee Kombucha, it doesn’t go bad in the traditional sense of the coffee world. Your coffee won’t be a rotten mess, but it won’t be suitable for drinking either.

Even when you store your coffee in the fridge, the fermentation process can continue but at a much slower rate. So if you get extra curious and leave it there for a couple of months, you’ll find that your coffee isn’t even coffee anymore; it’s coffee vinegar.

Fermented coffee beans have the same shelf life as regular coffee beans, so you don’t need to worry too much if you store them right.

Had fun reading? You’ll love to read our piece on what is mocha coffee.

Bottom Line

The idea of coffee processed with bacteria can sound pretty gross. But fermented coffee is a fine gift of nature that can bring you multiple health benefits, along with a rich, refined taste that enhances the coffee experience.

After reading this article, have fun if you are looking to try out fermented coffee!



What Is the Monsoon Process in Fermentation?

The monsoon process is a fermentation process performed in India. In this process, coffee beans are not thoroughly soaked in water and completely wet. Rather, they are moist, and the fermentation process uses fungi instead of bacteria and yeasts.

How Long Does It Take To Ferment Coffee?

It takes around 24-48 hours for coffee to ferment completely if done artificially. Natural fermentation depends on the amount of heat and water that affects the coffee.

Where to Buy Fermented Coffee?

Many stores now offer fermented coffee beans. If a local purchase isn’t an option, you can always order online.

What Is Cultured Coffee?

“Cultured coffee” is a term used to address fermented coffee. So fermented coffee and cultured coffees are one and the same.

How Does Fermentation Happen Naturally?

There are millions of bacteria, yeasts, and other microorganisms in the environment. To ensure survival, they latch on to different natural elements and break down the enzymes of the element to get nutrients while creating byproducts. This is considered natural fermentation.

What Beans Are Best Suited to the Process of Carbonic Maceration?

Carbonic maceration can go well with almost any coffee bean, making this process more popular among fermented coffee manufacturers.