Fermented Foods
Fermented foods are those that have undergone transformation through the action of microorganisms. Fermentation typically involves bacteria, yeast, or mold, and through this process, the taste, aroma, texture, and nutritional content of food can change or become enriched.
Representative fermented foods include kimchi, doenjang (soybean paste), ganjang (soy sauce), makgeolli (Korean rice wine), cheese, yogurt, and pickles. During fermentation, beneficial microorganisms are produced, making these foods known for containing probiotics, which are helpful for gut health. Fermentation also improves shelf life and enhances umami flavor, giving fermented foods their unique and rich taste.
What is Fermentation?
Fermentation refers to the chemical transformation of organic matter through the activity of microorganisms such as bacteria, yeast, or mold. In this process, microbes break down components like sugars, proteins, and fats to produce substances such as alcohol, organic acids, and gases. Fermentation can occur naturally or be induced under controlled conditions.
There are two main types of fermentation:
- Alcoholic Fermentation: This is the process where yeast breaks down sugars to produce alcohol and carbon dioxide. Beverages like makgeolli, beer, and wine are made through alcoholic fermentation.
- Lactic Acid Fermentation: In this process, certain bacteria convert sugars into lactic acid. Foods like kimchi, yogurt, and cheese are products of lactic acid fermentation.
Fermentation does more than just alter food — it enriches flavor and aroma, increases nutritional value, and improves shelf life.
Why Are Fermented Foods Good for You?
- The raw ingredients used in fermentation are already healthy.
For example, kimchi is made from ingredients like napa cabbage, radish, garlic, and green onions. Doenjang and cheonggukjang (fermented soybean paste) are made from soybeans. Cheese and yogurt are made from milk, and wine is made from grapes. - During fermentation, beneficial lactic acid bacteria increase.
As these microbes grow, they break down the raw ingredients into more easily digestible forms. They also suppress harmful bacteria in the gut, contributing to better digestion and a healthier gut environment. - Additionally, fermentation helps make nutrients more bioavailable. For example, beneficial nutrients like B vitamins can increase during fermentation, and some proteins are broken down into forms that are easier to digest.
- Fermented foods contain powerful antioxidants.
These antioxidants help reduce free radicals, which can damage cells in the body. Moreover, fermentation can generate substances that help boost the immune system.
What is Maturation (Aging)?
Maturation refers to the chemical changes that occur through internal enzymes without the involvement of microorganisms.
A representative example is wine. In many cases, fermentation and maturation happen together. Foods like kimchi, jang (fermented sauces), and jeotgal (fermented seafood) first undergo microbial fermentation. Over time, the enzymes produced by these microbes continue to act on the food, leading to gradual maturation.