What Is Food Fermentation? Cooking and the Process Behind Fermentation

Discover how fermenting foods can unlock unique and complex flavors, transforming ordinary ingredients into something entirely new.

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February 8, 2024 8 min read

Picture this: you just sat down at the ballpark to watch your favorite team. You have a hotdog slathered in mustard and your secret weapon, sauerkraut! The slightly sour, acidic punch from that sauerkraut always elevates the taste of a ballpark frank.

Or maybe, you’re at your favorite Korean restaurant and, along with your entree, the server sets out a small dish of spicy kimchi. Alongside some succulent protein and fluffy rice, the kimchi’s spicy crunch brings your meal to the next level.

Both of these examples center on the magic of fermented foods! Fermentation is an essential technique to learn in any chef’s skill set, and there are so many foods and beverages that are born through this delicate process.

Let’s explore how food fermentation works and the ways it can create completely new flavors.

How Fermentation Was Discovered

Fermented foods date back to at least 10,000 B.C.E. with humans using milk from camels, cows, and other mammals in the fermentation process. It wasn’t until the mid-1800s that people began getting a handle on exactly what was going on with foods they fermented. While early examples of fermentation were often happenstance, people slowly figured out how to use fermentation to preserve food and create tasty concoctions.

Fermenting vs. Pickling: What’s the Difference?

Some pickled foods can be fermented, and some fermented foods can also be pickled. The difference is in acid. Pickled goods are often made with a vinegar brine or similar acid solution, but fermented foods don’t add acid to the process (acid could kill the microorganisms responsible for proper fermentation!). Kosher pickles are considered both pickled and fermented because they rely on a salt brine with no added acid and no microorganisms at play.

Today, you would be pretty hard-pressed to find someone in your daily life who doesn’t regularly eat some kind of fermented food. One of the most obvious examples is the traditional Kosher pickle. According to the USDA, the average American consumes nine pounds of all types of pickles per year. But the most common example of fermented foods? Bread. This food can be found in some form or fashion in practically every culture around the globe.

A loaf of sourdough bread with decorative leaf scoring sits on a metal cooling rack on a marble countertop.

Sourdough bread is one of the most common examples of fermented foods in our diets. This loaf was baked and photographed by Danny N., Escoffier Online Baking & Pastry Graduate

How to Ferment Food

So, you may be wondering what fermentation really is then? Fermentation is a process in which microorganisms act as a collective to break down proteins, fats, and carbohydrates in food. It’s through this process that new flavors are awakened. These microorganisms are things like bacteria and fungi. It may sound gross, but without them, you wouldn’t have cheese!

The Three Main Forms of Fermentation

Fermentation takes on a number of different forms, but these three processes are among the most common:

  1. Lactic acid fermentation: This form of fermentation involves the conversion of starches or sugars by yeasts and other bacteria resulting in lactic acid. Foods that use this methodology include sauerkraut, kimchi, pickles, yogurt, and sourdough bread.
  2. Ethyl alcohol fermentation: In this form of fermentation, yeast breaks down molecules from sugars or starches and generates alcohol and carbon dioxide molecules. This is most commonly used to make beer and wine.
  3. Acetic acid fermentation: In this method, fermentations of sugars and starches from grains or fruit can lead to the development of tangy vinegars. This is most commonly seen in apple cider vinegar or kombucha.

Let’s use kombucha as a quick example of the process. If you brewed a gallon of tea and dropped in a cup of sugar, then left that gallon out in the open air for a month or two, opportunistic bacteria would go after the sugar. You’d likely end up with something that smelled awful and was dangerous to consume. But if you controlled the bacteria introduced to the tea, you could control the resulting beverage.

A large jug labeled “Kombucha” sits on a countertop next to some bottles and glasses all containing the same amber liquid.

Kombucha is the result of sweet tea undergoing an acetic acid transformation at the hands of very specific bacteria.

This is how kombucha is made. A small culture of beneficial bacteria—typically called a “scoby”—is added to a sweetened tea mixture and kept in ideal conditions (certain warmth, humidity, etc.). From the start, that good bacteria far outnumber anything opportunistic that could come by, and over time, it eats the sugar and grows larger, forming a thick layer at the top of the tea known as “the mother.”

After enough time has passed, the mother will have consumed nearly all the sugar present, releasing acetic acid, and the Kombucha can be bottled. At this point, the mother bacteria should have a smaller disc of fresh bacteria growing on its underside. This can become the scoby for a future kombucha batch.

Some slightly more advanced fermentation methods might not seek to control the bacteria present, but these are processes that should only be attempted by professionals.

What Common Foods Involve the Process of Fermentation?

A black bowl of kimchi—fermented cabbage and other vegetables bathed in chili sauce—sits next to a pair of chopsticks and a bowl of rice.

Kimchi is a classic example of fermented food from Korea.

Fermented food has stood the test of time and is an incredibly popular preservation method across the many diverse cultures and countries around the world.

If you’re curious about some key examples of fermented food, simply look in your pantry or refrigerator. Do you have beer, bread, some cured meats like salami? Are there any briny pickles or pickled onions? Do you have yogurt for breakfast or as a quick snack during the day? These are all examples of fermented foods that are omnipresent in our daily lives.

Examples of Commonly Fermented Food

Here are some common examples of fermented foods found all over:

  • Bread
  • Some pickles
  • Kimchi and sauerkraut
  • Yogurt
  • Cured meat like salami
  • Certain beer and wine
You may be wondering why fermented foods are so popular across the world. Outside of the preservative qualities talked about earlier, research has shown that fermented foods might also have many health benefits.

Can Fermented Foods Be Good for You?

In your daily life, you may have heard people talking about the importance of good “gut health” or “probiotics” and wondered what they are talking about.

Probiotics are living bacteria (and sometimes yeast) that have a symbiotic relationship with you. These aren’t the germs that get you sick. In fact, according to a study in the scientific journal Nutrients, having an abundance of good bacteria can actually help stave off illness by increasing the production of immunoprotective metabolites. It can also improve mental health, increase digestive comfort and efficiency, and even improve your skin. And fermented foods offer you a natural source of probiotics, without necessarily taking them as a supplement.

Fermented foods, such as sauerkraut and kimchi, are also rich in vitamins like vitamin C and B vitamins, which are produced or enhanced during the fermentation process.

A big aspect to remember when it comes to fermentation of foods, however, is the importance of cleanliness and proper sanitation. While fermented foods taste great, you are dealing with bacteria and fungi that can be harmful to you if not handled with care.

Before starting any fermentation process, it’s important to have a strong grasp on the technique, any potential pitfalls along the way, and good documentation of your methods as the fermentation process takes place.

Exploring More Culinary Techniques

Fermentation is a powerful technique that can allow you to create potentially beneficial foods that don’t compromise on flavor and texture—if anything, they can enhance it! And by adding these skills to your culinary toolkit, you can place yourself within a rich history of culinary arts that reaches back thousands of years.

The craft can take a long time to perfect, as can so many worthwhile cooking methods. If you’re attending culinary school, then you may have plenty of opportunities to see the ins and outs of this and other approaches to cuisine that can take your dishes to new heights.

Escoffier is a great place to start for anyone interested in pursuing a culinary education, whether you’re just starting out or an established pro always looking to improve. Reach out today to discover what awaits you!


This article was originally published on October 5, 2016, and has since been updated.

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