What You Never Knew About Your Favorite Brew

Content reviewed by Donna Gates
Written by Body Ecology on September 13th, 2022

cultured coffee

Did you know coffee is a fermented food? That’s right – your cup of joe is the result of coffee beans undergoing fermentation, followed by drying, roasting, grinding, and, finally, brewing. This makes coffee quite different from tea, which undergoes an enzymatic oxidative process instead of fermentation. 

And it’s thanks to this fermentation that coffee tastes so good, smells amazing, and has some unique health benefits.

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How Is Coffee Fermented? A Peek Into The Process

Fermentation of coffee (and cocoa!) involves a collaboration between fungi, yeasts, acetic acid bacteria, and lactic acid bacteria.

Once coffee fruit is picked:

– Farmers either spread out the beans and leave them to ferment in the sun or transfer them to a large tank of water where all the fruit briefly ferments together. 

– This method (using bacteria and other microorganisms found naturally in water, soil, air, and the coffee plant itself) helps to efficiently break down the coffee cherry pulp, making it easier for the beans to be stored and transported.

– After the pulp of the coffee fruit is removed, the beans are allowed to ferment for a further 12 to 48 hours. The fermentation time depends on the nature of the beans, the climatic conditions, and the desired flavor. Coffee connoisseurs are very particular about the fermentation process, and understandably so. 

Coffee beans are naturally covered with mucilage that contains a lot of sugar made up of polysaccharides (pectin), cellulose, and starch. When left to ferment, these sugars are broken down to give the bean a fuller, richer, deeper flavor. But leave those beans in the sun (or water tank) for too long, and there’ll be so little sugar left that it’s not possible to properly roast the coffee beans during the next stage of processing. 

Traces of the mucilage make it harder for coffee beans to dry quickly. They also make mold development much more likely, which can ruin coffee and contribute to higher levels of dangerous aflatoxins for us when we drink it. 

There are over 50 yeasts and bacteria commonly involved in natural coffee fermentation, including many Bacillus species.

The lactic acid bacteria can produce a wide variety of compounds in the coffee beans. This has led some to make a serious science of coffee processing, exploring the effects of specific kinds of lactic acid bacteria on the resulting coffee. 

Cultured Coffee Takes It A Step Further 

Cultured coffee is similar to conventional fermented coffee in that it undergoes microbial fermentation. The difference is that:

– Cultured coffee beans are only exposed to select microbes, meaning the coffee is specially engineered to taste and smell a certain way. 

– Cultured coffee promoters also claim that this kind of controlled fermentation leads to coffee with special characteristics, such as lower caffeine, less acrylamide, and higher levels of nutrients like vitamin B3 (niacin) and the non-jittery stimulant theophylline

Unfortunately, there’s little, if any, research to back up those claims as coffee culturing is still in its infancy.

Cultured coffee does tend to be less bitter and less acidic than conventional coffee, though, whether it’s a light, medium, or dark roast. This is because the microbes selected for the task of culturing are known to digest compounds in the beans that are responsible for coffee’s bitterness. These microbes also enhance the presence of other compounds that add to the richness of the aroma and taste of the coffee. 

Cultured coffee may be easier on the gut, with more sweetness and less need for added sugar or sweeteners. Makers of cultured coffee claim that it’s better for those with IBS and acid reflux. 

In one study, researchers used selected lactic acid bacteria (LAB) to improve coffee bean fermentation during on‐farm wet processing. The winning LAB was Lactobacillus plantarum LPBR01, which was seen to support production of organic acids and flavor‐active esters in coffee pulp. 

This bacterium proved to be an effective starter culture — helping to speed up fermentation time from 24 to just 12 hours, while significantly increasing the formation of aromatic compounds and other compounds beneficial to the final taste and quality of the coffee.

Another coffee fermentation starter culture shown to accelerate fermentation included a mixture of three Saccharomyces species (viz., S. marxianus, S. bayanus, and S. cerevisiae var. ellipsoideus).

BeetBioticIt’s important to note that cultured coffees are not a probiotic. To obtain essential beneficial microbes from a food source, we highly recommend you: 

  1. Add 3 ounces of a probiotic liquid to your meal each day.
  2. Eat cultured veggies (only a spoonful or two does the trick!). 
  3. Take probiotic supplements 
  4. Add Ancient Earth Minerals to your cup of coffee as a prebiotic to feed the bacteria

One company that we found that makes cultured coffee here in the US is eatCultured

The Coffee You’ll Probably Pass On….

If you’ve never heard of civet coffee, prepare to be either appalled or intrigued. This unique kind of coffee, known as kopi luwak, is the result of natural fermentation that happens inside an animal called a civet. These critters have a cat-like body, a raccoon-like face, fur with a leopard pattern, and a very long neck. They mainly live in tropical climates in Asia and Africa and find coffee fruit absolutely delicious. 

Civets are also coffee connoisseurs, meaning that: 

– They only eat the best coffee fruit. 

– They leave any bad fruit well alone, ensuring that all the beans collected from civet poop are the cream of the crop. 

Obviously, the beans are thoroughly washed before being roasted (which sanitizes the beans further). 

Want to make ANY coffee better? Add Ancient Earth Minerals (liquid) to support your adrenal glands, thyroid, and immune function. The electrolyte-rich formula aids in alkalizing, cleansing, and transporting nutrients. It contains a complete blend of humic, fulvic, micro, macro minerals, and amino acids. Best of all, it’s tasteless and dark so it disappears into your coffee.

Civet coffee is often touted as the best coffee in the world, with a rich amino acid profile, less acidity than conventional coffee, and a gentler effect on the digestive system. It’s important to note, though, that the profit to be made on this coffee can and does lead to animal abuse. Civets in the wild will happily eat the best fruit they can find, ignoring bad fruit. When civets are caged and force-fed coffee fruit, they’ll eat whatever they need to in order to survive. The result is unhappy animals and bad coffee that’s far from natural. If you’re interested in kopi luwak, be sure to look for cruelty-free options.

To Sum It Up

Improvements to the process of coffee fermentation not only help accentuate the sensory aspects of coffee, such as taste and aroma, they also help lower the risk of microbial contamination and spoilage. Using an effective starter culture to expedite coffee fruit fermentation means more efficient breakdown of the mucilage around the beans. 

This mucilage is made up of polysaccharides (pectin), cellulose, and starch, and traces of these make it harder for coffee beans to dry quickly. They also make mold development much more likely, which can ruin coffee and contribute to higher levels of dangerous aflatoxins. 

Roasting does arrest the growth of residual mold that produces aflatoxins but doesn’t eradicate the aflatoxins themselves. As such, a carefully controlled fermentation process using LAB and other beneficial microorganisms may just be the best way to keep coffee aflatoxin-free.



Vinícius de Melo Pereira, G, Pedro de Carvalho Neto, D, Bianchi Pedroni Medeiros, A, et al. Potential of lactic acid bacteria to improve the fermentation and quality of coffee during on‐farm processing. Food Science and Technology, July 2016, 51(7): 1689-1695. https://doi.org/10.1111/ijfs.13142Citations: 30

D. Agate and J. V. Bhat, “Role of pectinolytic yeasts in the degradation of mucilage layer of Coffea robusta cherries,” Applied Microbiology, vol. 14, no. 12, pp. 256–260, 1966.

Mesfin Haile, W. Kang. The Role of Microbes in Coffee Fermentation and Their Impact on Coffee Quality. March 2019; Journal of Food Quality 2019(12).

Silva CF, Batista LR, Abreu LM, Dias ES, Schwan RF. Succession of bacterial and fungal communities during natural coffee (Coffea arabica) fermentation. Food Microbiol. 2008;25(8):951-957. doi:10.1016/j.fm.2008.07.003.

Soliman KM. Incidence, level, and behavior of aflatoxins during coffee bean roasting and decaffeination. J Agric Food Chem. 2002;50(25):7477-7481. doi:10.1021/jf011338v.

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