käymisessä

Käymisessä, often translated as fermentation, is a metabolic process that converts sugar to acids, gases, or alcohol. It occurs in yeast and bacteria, and also in oxygen-starved muscle cells, as a means of energy production. In the context of food production, it refers to the controlled breakdown of carbohydrates by microorganisms.

This process is crucial for producing a wide variety of foods and beverages. For example, alcoholic fermentation by yeast produces ethanol and carbon dioxide, which are the basis for making bread, beer, and wine. Lactic acid fermentation, carried out by lactic acid bacteria, converts sugars into lactic acid. This is fundamental to the production of yogurt, sauerkraut, kimchi, and many other fermented dairy products and vegetables.

Beyond food, fermentation plays a role in industrial processes, such as the production of biofuels like ethanol and in the manufacturing of certain chemicals. The microorganisms involved, often specific strains of bacteria or yeast, are selected for their efficiency and the desired end product. The conditions under which fermentation occurs, such as temperature, pH, and the availability of nutrients, are carefully controlled to optimize the process and ensure the quality and safety of the final product. Understanding käymisessä is key to appreciating many traditional food preservation techniques and modern biotechnological applications.