Fermentation is the conversion of carbohydrates into alcohol and carbon dioxide. This process happens using bacteria or yeasts, or a combination of the two under anaerobic conditions. Occasionally, the term fermentation may also include the chemical conversion of sugars into ethanol. This process is used to make beer, wine, and cider. Food fermentation is also involved in the process of leavening bread and the process of producing lactic acid in foods such as dry sausages, sauerkraut, yogurt, pickles, and kimchi.
Since the dawn of time, humans have used food fermentation to make and store foods. For example, one of the earliest fermented foods was an alcoholic beverage made from honey, fruit, and rice. This was made around 7000-6600 BCE in a Chinese village. Even jars unearthed in Iran estimated to be over seven thousand years old have been found containing wine remains.
Louis Pasteur, a French chemist, was one of the first known men to connect yeast to fermentation. With his studies of this food science, Pasteur concluded that a vital force, called “ferments” catalyzed the process of fermentation. He believed that these “ferments” could only function within living organisms. However, it is well known that the extracts of yeast have the ability to ferment sugar without the absence of living yeast cells.
Fermentation in food is thought to serve five purposes. One, it is thought to enrich the diet with the development of aromas, textures, and flavors in food substrates. It also helps to preserve food with the help of alcohol, lactic acid, alkaline, and acetic acid fermentations. In addition, fermentation also adds biological enrichment of food with vitamins, protein, and amino acids. Another benefit of fermentation is the elimination of antinutrients from food that can interfere with the absorption of nutrients in the body. Fermented foods also provide a decrease in fuel requirement and cooking time.
Fermented foods can be found around the world. Common food staples found in nearly every country are wine, alcohol, yogurt, cheese, bread, and olives. East and Southeast Asia provide a plethora of fermented foods, such as tempeh, miso, stinky tofu, kimchi, and tape. Many of which are fermented soybean products.
Popular fermented foods in the Americas are cultured milk, chichi, sourdough bread, sauerkraut, chocolate and vanilla. In Europe, fermented foods like sauerkraut, quark, kefir, salami, and prosciutto are very popular.
Fermentation is one of the oldest methods of processing food into a preserved form. In addition, it helps foods that might be hard to digest become much easier to digest. One example of this is porridge, which hydrolyzes starch into shorter chains of dextrose and glucose.
Along with health benefits, fermented foods have the benefit of changing flavors to become more complex. Some fermented foods develop an umami flavor, such as fish and soy sauce. These help to bring a meatier flavor to dishes that do not have meat.
Although the chemistry of fermentation can be complex, the process is relatively easy and happens quite naturally. This is the reason human beings have used the process of fermentation in food production since as far back as we can remember. Many people enjoy fermented foods, and they have become staple foods in our lives.