Fermentací

Fermentací, the Czech term for fermentation, describes a metabolic process in which microorganisms such as yeast, bacteria, or molds transform carbohydrates into new compounds, often with energy production under anaerobic conditions. Fermentation can preserve food, improve flavor, and alter texture by shifting chemical equilibria and reducing water activity. It is distinct from respiration in relying on substrates other than oxygen to transfer electrons and often producing byproducts such as alcohol, organic acids, and gases.

The most common forms are alcoholic fermentation, lactic acid fermentation, and acetic fermentation. In alcoholic fermentation, yeast converts sugars into ethanol and carbon dioxide, used in bread, beer, and wine. Lactic acid fermentation reduces pyruvate to lactate, practiced by lactic acid bacteria in yogurt, sauerkraut, kimchi, and pickles. Acetic fermentation oxidizes ethanol to acetic acid, as in vinegar production. Mixed fermentations can generate a range of flavors and textures; propionic fermentation in certain cheeses forms holes and distinctive aromas.

Historically, fermentation has been used for food preservation long before modern microbiology. Louis Pasteur demonstrated that microbes drive fermentation, linking it to specific organisms rather than spontaneous processes. Today, fermentation underpins industrial biotechnology, enabling large-scale production of alcohols, organic acids, enzymes, antibiotics, and biofuels.

Applications span culinary and industrial contexts, from bread and dairy products to soy-based condiments and fermented vegetables, with ongoing research to optimize yields and flavors. Safety relies on controlled conditions, hygienic practices, and the use of starter cultures to minimize unwanted or harmful microbes; however, uncontrolled fermentation can lead to spoilage or toxin formation.