Fermented Foods: Ancestral Preparation for Modern Digestion

There is nothing new about fermentation. It is one of the oldest food preparation methods known to humanity — born from necessity, refined through observation, and sustained because it works.

Long before refrigeration, our ancestors relied on salt, time, and the natural environment to preserve and transform food. Today, modern research continues to explore how these traditional practices intersect with digestive health and the gut microbiome. What was once survival wisdom has become a meaningful tool for nourishment in our present day.

Diana’s years of research and daily application have reinforced a simple truth: ancient food wisdom still works — and it can be applied simply to our meals today.

What Is Fermentation?

Fermentation is a natural metabolic process in which microorganisms — such as beneficial bacteria or yeasts — convert sugars and carbohydrates into acids, gases, or alcohol. 

In food, fermentation:

• Preserves ingredients naturally

• Enhances flavor and texture

• Alters nutrient composition making it more easily absorbed and digested

• Introduces beneficial bacteria to our gut microbiome

As we discussed in our blog post on Celtic Salt: What Makes It Different?, mineral-rich salt has long been foundational in traditional preservation methods. When salt and water are added to vegetables, for example, naturally present bacteria begin to convert sugars into lactic acid. This acidic environment preserves the food while creating its characteristic tang.

Fermented foods are valued because they contain live microorganisms (when unpasteurized), which contribute to the diversity of microbes in our diet.

A Brief History of Fermentation

Across ancient cultures, fermentation was foundational:

• Vegetables were salted and stored in water-tight ceramic containers.

• Milk became yogurt and kefir.

• Cabbage transformed into sauerkraut and kimchi.

• Grapes fermented naturally into wine — historically much lower in alcohol than many modern versions.

• Bread was traditionally fermented before baking to leaven the dough, enhance flavor, improve digestibility by reducing gluten, and extend “shelf life.”

When refrigeration wasn’t available, salt — often harvested from the sea — was essential for preservation. Its abundance made it practical and powerful.

Traditional bread fermentation is a perfect example. Flour, water, and mineral-rich salt were mixed and left to rest for 14–17 hours. During that time, natural fermentation began, breaking down components of the flour, like gluten, and developing flavor before the bread was baked.

Even honey plays a role in preservation. Raw honey has an exceptionally long shelf life due to its low moisture content and natural properties — it does not spoil under proper storage. Nature, in many ways, built its own systems of protection.

Fermentation & The Gut Microbiome (A Practical Overview)

The gut microbiome refers to the diverse community of microorganisms living in the digestive tract. These microbes interact with food, influence digestion, and contribute to overall balance within the body.

Fermented foods introduce live bacteria that can add diversity to the microbes we consume. While research in this area continues to evolve, many nutrition professionals encourage dietary diversity — including fermented foods — as part of a whole-food eating pattern.

Importantly, fermented foods are not a cure or treatment. They are simply traditional foods that may support whole-body balance when included regularly and thoughtfully.

As Diana shares: ferments offer beneficial bacteria that our gut uses daily as part of maintaining microbial balance.

Types of Fermentation

Traditional fermentations are all natural processes typically relying on natural yeasts, salt, and time. Fermentation can be either anaerobic (without oxygen) or aerobic (with oxygen) depending on the stage of the ferment. For example, in the process of making vinegar, the first stage is alcohol formation (anaerobic) in which yeast breaks down sugars in the absence of oxygen to produce ethanol (alcohol) and carbon dioxide. In the second stage, Acidification (aerobic), Acetobacter (bacteria) oxidizes the ethanol in the presence of oxygen, turning it into acetic acid. Anaerobic fermentation is a metabolic process that breaks down organic compounds (like glucose) to produce energy (2 ATP) without oxygen, primarily yielding lactic acid, ethanol, or other organic acids/gases. 

There are several forms of anaerobic fermentation used in traditional food preparation. Here are 4 types that can be used today:

1. Lacto-Fermentation

Lacto-fermentation is  a natural, anaerobic process where Lactobacillus bacteria convert sugars and carbohydrates in food into lactic acid. It acts as a preservative that enhances flavor, creates a tangy, umami-rich taste, and boosts probiotic, vitamin, and enzyme levels. Common examples include sauerkraut, kimchi, pickles, and yogurt. Vegetables can be lacto-fermented simply with mineral-rich salt, water, and time. Salt creates a hostile environment for harmful microorganisms while encouraging beneficial bacteria to flourish. How amazing is that!? The beneficial bacteria convert lactose to lactic acid, preserving the food and giving this process its name.

2. Wild Yeast Fermentation

Wild yeast fermentation is a traditional, spontaneous process utilizing native yeasts present on food surfaces (like grape skins or fruit) or in the environment, rather than added commercial yeast. This type of fermentation is often used in sourdough bread, traditional wines, kombuchas, and other brews. Unlike cultured yeast, wild yeasts are gathered from the environment and result in a very diverse profile which is beneficial for our gut microbiome. These naturally occurring yeasts convert sugars into carbon dioxide naturally creating that signature bubbly effect.

3. Alcohol Fermentation

Traditional alcohol fermentation was used to convert sugars (glucose, fructose, sucrose) from fruits or grains into ethanol and then to carbon dioxide. While modern techniques allow for controlled, higher alcohol content, historic beverages often had lower, less concentrated alcohol levels. This is because traditional alcohol fermentation typically stops when alcohol levels reach 12–15%, as higher concentrations become toxic to the yeast.

While it's hard to call any alcohol “healthy,” traditional alcohol fermented beverages (like raw, unfiltered wine or traditional beer) is generally considered slightly "less bad" or potentially healthier than modern, heavily processed alcohol due to higher levels of beneficial polyphenols and antioxidants. Moderation is always key when it comes to alcoholic beverages. 

4. Honey Fermentation

When raw honey is combined with ingredients like garlic or herbs (and moisture is introduced), a gentle fermentation can occur over time. Fermentation using honey involves the natural, wild yeast and enzymes within raw honey (SO COOL!)  converting sugars into alcohol and carbon dioxide when exposed to moisture (above 19% water content) and warmth. This process creates probiotic-rich, tangy, and sometimes bubbly fermented honey products, such as garlic or fruit ferments, which are excellent for gut health and immune support.

If you enjoy warming, traditional preparations, you may also love our Flu & Cold Drink: A Warming Wellness Tea for Cold Season, a simple recipe rooted in traditional ingredients and seasonal support.

How to Incorporate Fermented Foods Daily

Consistency matters more than quantity when it comes to fermented foods. Small, daily additions are often sufficient. To increase fermented food intake, start slowly with one serving daily of items like kefir, yogurt, sauerkraut, or kimchi, gradually increasing to avoid digestive discomfort. Incorporate these foods into meals as condiments, such as topping sandwiches with sauerkraut, mixing miso into soups, or swapping processed yogurt for kefir. Aim for variety to consume different probiotic strains. 

If you’re excited to start these traditional fermentation processes in your own kitchen, try one thing at a time so as not to get overwhelmed. Whether it’s making your own SIBO yogurt, getting a sourdough starter, trying your hand at kombucha using a Scobi, or simply starting a fermented honey by adding garlic to your next jar — your gut, health, and spirit will be overjoyed! 

Whether you want to try your hand at traditional fermentation processes or not, you can still add fermented foods to add to your diet. Here are some practical ways to include ferments:

• Add a spoonful of kimchi or sauerkraut to lunch bowls

• Include fermented vegetables alongside dinner

• Use fermented condiments in dressings

• Add yogurt or kefir to your sprouted granola

• Get creative with fermented honey on meals and snacks

Ferments are powerful in flavor and health benefits — a little goes a long way.

Salt of the Earth Wisdom

Fermentation is not complicated. It requires time, salt, and trust in natural processes.

Our ancestors did not have modern preservation systems. They relied on what was abundant — salt from the sea, raw honey, wild yeast, and patience. Today, we can choose to reintroduce these slow practices into fast lives.

Fermented foods are foundational.

Incorporating them daily is less about trends and more about reconnecting to simple preparation methods that have nourished generations before us.

If you’ve been curious, start small. Add one ferment to one meal this week. Observe. Taste. Learn. Ancient wisdom still has a place at the modern table.

Remember, you are the salt.

You add the flavor.

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Sources & Further Reading

This article draws from published research in food microbiology, fermentation science, and nutritional studies including works from the Journal of Cereal Science, Frontiers in Microbiology, Current Opinion in Biotechnology, and historical fermentation texts by Sandor Katz and others.:

What is Fermentation?

Fermentation is a natural metabolic process… You can read more about traditional fermentation methods and safety from the National Center for Home Food Preservation (University of Georgia).👉 https://nchfp.uga.edu/how/freeze/fermentation.html

Gut Microbiome Basics

The gut microbiome refers to the diverse community of microorganisms living in the digestive tract… For more on current microbiome research, see the National Institutes of Health’s Human Microbiome Project overview. 👉 https://commonfund.nih.gov/hmp/overview

On the history of fermentation & traditional food preservation

1. Hutkins, R. W. (2018). Microbiology and Technology of Fermented Foods (2nd ed.). Wiley-Blackwell. – Comprehensive academic reference on fermentation processes and global history.

2. Katz, S. E. (2012). The Art of Fermentation. Chelsea Green Publishing. – Historical and anthropological overview of fermentation practices across cultures.

3. McGovern, P. E. (2009). Uncorking the Past: The Quest for Wine, Beer, and Other Alcoholic Beverages. University of California Press. – Archaeological evidence of early wine and alcohol fermentation.

4. National Center for Home Food Preservation (University of Georgia). – Historical preservation practices prior to refrigeration.

On the science of fermentation & microbial processes

5. Marco, M. L., et al. (2017). “Health benefits of fermented foods: microbiota and beyond.” Current Opinion in Biotechnology, 44, 94–102. – Overview of how fermented foods interact with gut microbiota (non-therapeutic framing).

6. Tamang, J. P., et al. (2020). “Fermented foods and beverages of the world.” Frontiers in Microbiology, 11: 579. – Classification and mechanisms of global fermentation types.

7. Wolfe, B. E., & Dutton, R. J. (2015). “Fermented foods as experimentally tractable microbial ecosystems.” Cell, 161(1), 49–55. – Explanation of wild yeast and microbial diversity.

On lactic acid fermentation & salt preservation

8. Di Cagno, R., et al. (2013). “Lactic acid fermentation: microbiological and functional aspects.” Current Opinion in Biotechnology, 24(2), 160–167.

9. Caplice, E., & Fitzgerald, G. F. (1999). “Food fermentations: role of microorganisms in food production and preservation.” International Journal of Food Microbiology, 50(1–2), 131–149.

On gut microbiome basics

11. Thursby, E., & Juge, N. (2017). “Introduction to the human gut microbiota.” Biochemical Journal, 474(11), 1823–1836.

12. Valdes, A. M., et al. (2018). “Role of the gut microbiota in nutrition and health.” BMJ, 361:k2179.

On honey preservation & fermentation

13. Molan, P. (1992). “The antibacterial activity of honey.” Bee World, 73(1), 5–28. – Explains honey’s low moisture and preservation properties.

14. Snowdon, J. A., & Cliver, D. O. (1996). “Microorganisms in honey.” International Journal of Food Microbiology, 31(1–3), 1–26. – Discusses honey’s water activity and microbial stability.

On alcohol fermentation limits

15. Pretorius, I. S. (2000). “Tailoring wine yeast for the new millennium.” Yeast, 16(8), 675–729. – Discusses ethanol tolerance limits in yeast (~12–15%).