What is Fermentation and Why Eat Fermented Foods?

In the words of our friend Michael Pollen, “Eat food. Not too much.  Mostly plans.”  We are glad this approach is becoming more popular as a larger portion of the population begins to embrace a lifestyle centered around plant-based foods.  At Project Umami, we believe the consumption of plants can benefit an individual’s physical and mental health. Our goal is to help bring those benefits to the communities we serve.  

Major Components of Fermentation:

  1. Flavor: Fermentation changes the flavors, aromas, and textures of the food.
  2. Preservation: Through lactic acid, acetic acid or alkaline fermentation, fermentation of foods prevents spoilage.
  3. Enrichment: Fermentation improves the nutritional value of cereal grains, legumes, and vegetables by increasing the protein content or availability of essential amino acids, essential fatty acids and vitamins.
  4. Detoxification: Fermented foods repair and feed our gut biota, giving our natural detoxification abilities a much-needed boost.

The first step to appreciating what fermented foods have to offer is understanding how the microbes responsible for fermentation alter food molecules.   Through fermentation, big molecules of proteins, starches, and fats are broken down into smaller, more digestible, enzymes, vitamins, and nutrients. 

Harold McGee, author of On Food and Cooking, points out that large molecules like proteins, starches, and fats do not have much flavor, but when these larger molecules are broken down  into their building blocks – proteins into amino acids, starches into sugars, fatty into free fatty acids – these smaller molecules all have intense and delicious flavor.   Thus, we are gifted the enhanced flavor profile of fermented foods.    

Sustainability and health, however, are even more compelling reasons to eat fermented foods. 

When grains and legumes are fermented, these humble ingredients become not only more delicious, but also nutritionally-charged.  In fact, their benefits can go beyond basic nutrition to health enhancement. Compelling accounts, like Fiber Fueled by Will Bulsiewicz, MD outlines the results of countless scientific studies touting the benefits of a diverse plant-based diet. For example, fermented foods and microbiota diversity have been found to effect modulation of stress – or anxiety-related behaviors –  in animals.

Not all fermented foods are probiotic.  Tempeh does not have live probiotics, yet it is touted as a food that helps strengthen digestion because it is easy to digest and contains heat-stable antibiotic agents that act against some diseases.

Tempeh is a mold fermentation.  Molds, which are a type of fungi, are multicellular and characterized by growing in a cobweb of filaments (often called a filamentous fungi).  In this context, to make tempeh, a substrate, be it beans or grains, is soaked in water and then boiled.  After which an edible species of mold is introduced called Rhizopus.  This mold takes in oxygen and transpires carbon dioxide.  Sounds like us, right?  That CO2 inhibits other microorganism growth.  To further outcompete other mold species, the Rhizopus species produces a lot of filaments, which cover the beans to such a degree that the beans are protected from any other molds.  Finally, as if just to make sure of complete defense, the Rhizopus expresses some antibacterial activity to inhibit other molds.  If the temperatures are kept in the right range and the mold is strong, it will also inhibit other microbes, like bacteria and yeast, from growing. 



Shockey, K., & Shockey, C. (2019). Miso, tempeh, natto, & other tasty ferments: a step-by-step guide to fermenting grains and beans. Storey Publishing: Page 15. 

Luna, R. A., & Foster, J. A. (2015). Gut brain axis: diet microbiota interactions and implications for modulation of anxiety and depression. Current opinion in biotechnology32, 35–41. https://doi.org/10.1016/j.copbio.2014.10.007