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Fermentation is an old-world technology that preserves food, deactivates toxins,  reduces cooking time,  improves nutrients, and adds flavor and texture to foods. Fermenting grains and other starches can be a life-changing choice for many people who struggle with gastrointestinal issues. Cultures allow beneficial bacteria (and other microorganisms) to assist with the digestive process making nutrients more easily accessible.

Because of the significant rise in diet-related chronic diseases, there is a considerable amount of research happening currently attempting to understand the complex connections between dietary choices and health. Many of the simplistic theories that underpin our current food system are being debunked. Nowhere is this more relevant than in ascertaining the role of grains and other starches in a health-promoting diet.

Since their domestication, cereal crops have become the primary source of calories in most diets. As a relatively easy way to ingest nutrients, most indigenous cultures developed food preparation techniques that make cereal crops more digestible.

The industrialization of food processing has distanced consumers from these traditional methods, in favor of quick to eat food with a long shelf life. Controversy has been stirring with regard to including grains in our diets, in part, because there has been a detrimental trade-off between ease of meal preparation and nutritional value.

As the “staff of life,” grains, are an integral part of any conversation about gut health and nutrition

Grains and Starches

Starches are insoluble polysaccharides (multi-chain sugars) stored as a reserve food supply in plants. They are the primary source of the macronutrient carbohydrate in our diets. Grains are considered to be starches, however, there are other non-grain carbohydrates that can benefit from fermentation.

Grains (alsa known as cereal crops) are generally grown from grasses that produce edible kernels including the seed embryo (the germ) fused with “ fruit” (the bran, and endosperm).

Cereals look similar to seed However, seeds differ from grains in that they provide nutrients primarily from the embryo part whereas seeds nutrients are primarily from the “fruit” part of the plant.

Cereal crops are the primary energy source in our modern food system and are an integral part of the diets of most of the world’s population. Globally, the most important modern grain crops are corn, rice, wheat, barley, and sorghum.

The History of Grains and Starches

The domestication of cereal grains is believed to have happened around 10000 years ago, in the Neolithic era. This changed the lives of our ancestors as they were now able to settle and form communities.

There is evidence that our ancestors may have eaten sorghum 105,000 years ago in Mozambique. Additional discoveries indicate that grains were consumed about 75,000 years ago in western Asia. These grains, including einkorn and emmer, are the original wheat. 

People began cultivating, or growing, grain more recently. In 2009, scientists announced that they had discovered the world’s oldest known grain silos at Dhra in what is now the nation of Jordan. The silos, which date back 11,000 years, contained remnants of barley and an early type of wheat. 

Other starchy foods have an equally important history. Tubers (potatoes, sweet potatoes, yucca, celeriac, turnips, taro and lotus root) are considered to be of ancient origins. These carbohydrates are so valued because of the wide variety of flavor and nutritional value. Squashes were domesticated about 8,000 years ago. All of these foods have been dietary staples for millennia.


Modern Grains and Starches

Since the advent of our modern food system with a focus on processing, pasteurization, irradiation, filtration to extend shelf life, we are now bombarded with a plethora of things to eat, most of which are nutritionally deficient.

Hybridization and chemical applications have greatly reduced the variety of grains that we consume today. Grains and other starches have been modified and bred for fast growth, ease of processing, pest resistance and other things that make food more abundant but not necessarily more nutritious or fit for human consumption.

Technology has allowed for the rapid separation and removal of the bran and germ from the endosperm in bulk. Refined grains (endosperm only) do not travel the full distance through the digestive tract, instead, the sugars are released in the small intestine causing higher calorie absorption.

Refined cereals have been stripped of most of the nutritional value of the kernel including fiber, B vitamins, Vitamin E, trace minerals, unsaturated fats, and ¾ or more of the phytochemicals. Whole grains can be a better source of protein, fiber, calcium, magnesium, potassium, and other antioxidants. 

Why Ferment Grains and Starches?

A Stable and Reliable Source of Nutrition

There is some debate as to whether or not grains are necessary at all in a modern diet. Paleo enthusiasts claim that if we were designed to eat grains we would have the necessary enzymes to digest them. There is at least one study, which seems to indicate that the elimination of grains and starches can offer some health benefits beyond weight loss as compared with the typical Western diet.

However, the fact is that grains are an inexpensive and dependable source of nutrients that cannot be ignored.


The qualities that make grains and other starches storable are the same qualities that make them more difficult to digest: low water content and hard, fibrous external coating. Most starches are considered indigestible without cooking. Heating the starch molecules causes them to change their cellular structure breaking the compounds into more single-celled components, which are easier to digest. 

Resistant Starches

Traditionally, humans consumed more unrefined carbohydrates that have a higher nutritional value and more resistant starch, that is digested in the large intestines by beneficial microorganisms. Fermenting grains and other starches produces additional vitamins, minerals, and short-chain fatty acids to support bodily functions. Resistant starches are believed to improve insulin resistance, elimination, and satiety.


Microbiome Support

Studies have shown that the microbes in our gastrointestinal tract love fiber. By the time our food reaches the large intestine only the indigestible parts remain, including fiber. Then the bacteria in our gut get to feast in a process of fermentation, creating the by-products acetate, butyrate, and propionate, the short-chain fatty acids (SCFAs), that our body uses to produce energy.

Some studies have shown that certain beneficial bacteria respond well to whole grain consumption. Two of the most important genus Bifidobacteria and Lactobacilli seem to thrive and multiply with whole grains. However, research is in the early days

Skeptics say that there are ways to ingest fiber for the gut microbes that do not require the consumption of grains. 


Antinutrients are compounds that bind with nutrients needed to support bodily functions, preventing them from being assimilated.

All life forms have some form of defense mechanism that protects the species from predators and disease. In plants, which have little ability to move, the defenses are primarily chemical. Ruminants (animals that chew cud) eat grasses and the antinutrients allow the seed to survive that digestion process and be eliminated by the animal in a form that is ready to grow.

There is evidence that fermenting grains and starches can have a significant impact on antinutrients. Specific bacteria in the fermentation process are able to modify or degrade antinutrients in plants, allowing for better digestion and absorption. The mechanism by which this occurs is not fully understood but researchers are working to uncover the specifics.

Antinutrients in grains and starches



Lectins are essentially proteins that bind to carbohydrates. Many plant-based foods contain lectins and must be cooked to be edible. There are some beneficial lectins that assist with protein synthesis, control protein levels in the bloodstream and support immune function.  There are, however, a number that are toxins including the well-known poison, ricin.

Phytic Acid

Phytic acid binds with calcium, iron, and zinc limiting their availability for absorption. Seeds have a higher level of phytic acid than most other starches.


Hydrocyanic Acid

Cassava is the carbohydrate that contains significant amounts of hydrocyanic acid in its raw form. Legumes may also contain the toxin. Cooking reduces these compounds.



The most commonly known antinutrient, gluten, is an enzyme inhibitor. The digestive problems related to gluten consumption are well documented. Fermenting grains has been shown to reduce the gluten content of most flours.


Enzyme Inhibitors

Many drugs and pesticides are enzyme inhibitors. Trypsin is widely found in pulses. Glycoalkaloids are found in nightshade plants include potatoes, tomatoes, and eggplants.

The Benefits of Antinutrients

As is typically the case, no story is one sided. Although they are called antinutrients, most of these compounds also have some positive biological and nutritional impact. Phytic acid, for example, is considered to be a powerful antioxidant that may help reduce risk factors for diabetes, heart disease, and obesity. But perhaps most importantly, reseachers have shown that many may provide protection against cancers.

There is some thought that the negative antinutrient effects of grains and other plant foods are primarily a problem for most of us in combination with a diet of mostly processed foods, a limited variety of foods, and poor nutritional value.

Types of Grains


Grain crops include wheat, oats, rice, corn, barley, sorghum, rye, wild rice, and millet.  Lesser-known types include einkorn, emmer, freekeh, teff, spelt, and triticale. These grasses belong to the Poaceae

Pseudo Cereal

Amaranth, quinoa, chia, and buckwheat belong to a group of cereals known as pseudo cereals which are nutritionally similar to cereals. Because they are less widely available some individuals experience fewer allergic reactions and intolerance to these varieties.


Pulses is a term that describes the high protein grain crops including beans, lentils, peas, peanuts, and soybeans.


Finally, there are a number of grain crops that are primarily used for their oils like flaxseed, rapeseed, mustard, hemp, poppy, safflower and sunflower seed.


Types of Non Grain Starches


These buried jewels, known as geophytes, pack a nutritional punch. Designed to store energy for stem growth, they absorb nutrients from the soil. Varieties include potatoes, sweet potatoes, yucca/cassava, parsnips, turnips, rutabagas, celeriac, lotus root and taro.


Squashes are another versatile starch. Although they are fruit by classification, they are a high starch fruit. Winter squashes are generally treated as starches, while summer squashes are considered low carbohydrate. Types of starchy squashes include pumpkin, butternut, and acorn.


Green bananas and plantains are good sources of resistant starch. It is best to cook them like any other starch.

How To Ferment Grains

Traditional methods for preparing grains to eat always involve some form of “predigestion” of the plant stuff. From chewing to grinding to fermenting the plants are transformed into something nutritious.  


Soaking merely involves submerging the grain in acidulated water for at least a few hours, allowing the bran to soften and water to penetrate the endosperm and eventually the germ. The water-soluble antinutrients in the outer layer are reduced and certain nutrients are activated. Soaking is widely used to reduce the sugars in pulses that cause flatulence.


Adding water to grains reactivates them and their microbes. Sprouting takes soaking to the next step by allowing the germ to begin the process of germination. Sprouting seems to have a significant impact on phytic acid, in particular, increasing phytase activity.


Fermentation improves nutrtional value to another level. Grains can also be fermented by adding an existing culture from kefir, kombucha, yogurt, or a starter culture.

Wild fermentation is another way to gather microbes for culturing grains. Our kitchens are filled with beneficial microbes that can be collected by sitting on the countertop.

“The simplest way to ferment grains is to soak them. Water is the source of all life, and the dry seed is able to persist intact precisely because, in the absence of water, the microbes inevitably present on the surface of it cannot function or grow. Yet they do remain dormant until restored to life by water, much like the seed itself. When you soak the grain, it begins to swell… At the same time, water also revives the bacteria and fungi that populate the grain’s surface, and initiate fermentation.” 

Sandor Katz, The Art of Fermentation

Types of Fermented
Grains and Starches

Most grains are used to make porridges, breads, and noodles. Perhaps the most popular use of fermented grains is in alcoholic and non-alcoholic beverages.

To get a sense of the types of grain dishes that can be fermented, we have to comb the globe. We in the West have lost touch with traditional foods, however, in Africa, Asia, and Latin America these foods are still a core part of the culture.



The predominant African grains are not as familiar as others. Millet, sorghum, and cassava are not commonly found in Western grocery stores.

Kenkey is a fermented porridge made from sorghum or corn.



We are probably most familiar with Asian fermented foods. Our love affairs with Japanese, Chinese, Korean, and Thai foods are a helpful introduction to fermented grains and starches.

The fermented soybean products are most well-known. Miso, tempeh, and natto are some of the more widely available ones.

Idli and dosa are fermented flatbreads made with rice and gram from Indian cuisine.

Latin America

Latin America

In Latin America by far the largest grain crop eaten is corn. Brazil is the world’s 4th largest producer of agricultural products.

Atole and pozol are fermented corn preparations used for multiple final dishes.

A healthy diet including grains should have multiple types of grains and starches to maximize nutritional intake.


Fermenting grains and other starches is an effective way to reduce the inflammatory response to the toxic components while improving the nutrition assimilation of these foods. In order to maximize the nutritional value of grains, it is best to combine a number of these methods of preparation including using heat to cook them. 

Eating a wider variety of foods can help reduce the risk of malnutrition and digestive sensitivity due to antinutrients. A healthy diet including grains should have multiple types of grains and starches to maximize nutritional intake.

FAQs Fermenting Grains and Starches

This is a selection of the most frequently asked questions about the benefits of cultured vegetables.

It is unlikely that wheat based sourdough bread is gluten free? However, there are studies that show that gluten levels are lower in soured dough than in commercially prepared breads.

Fermenting wheat does reduce the antinutrients and allergens and can be a more digestible alternative to yeasted breads. 

People who have Celiac’s disease should not eat sourdough without a doctors advice, because reduced levels of gluten does not mean gluten-free.

As a primary non-animal protein source, pulses are an important food. Soaking is known to help reduce some of the sugars that cause gas.

Fermentation takes the “pre-digestion” to the next level. Many cultural traditions include fermented pulses like miso, tempeh, etc. These foods provide more proteins, vitamins, minerals and enyzmes than non-fermented beans.

Its worth a try.



However, this is not a free license. Pseudograins do have antinutrients like most plant foods. Most need to be soaked, sprouted, fermented, and/or cooked to be digestible.

The good news is that pseudograins are a better source of protein, vitamins and minerals than the staple grains.

Devin J. Rose
Impact of whole grains on the gut microbiota: the next frontier for oats?

Norman F. Haard, S.A. Odunfa, Cherl-Ho Lee, R. Quintero-Ramírez, Argelia Lorence-Quiñones, Carmen Wacher-Radarte

Fermented Cereals. A Global Perspective


Tan J, McKenzie C, Potamitis M, Thorburn AN, Mackay CR, Macia L.

The role of short-chain fatty acids in health and disease.



The information on this website is NOT medical advice. It is not intended to diagnose, treat, cure, or prevent any disease. Before making any changes please seek advice from a medical professional.

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