<human>:  How does fermentation work?
<bot>: Fermentation is a process by which microorganisms such as yeast or bacteria convert the sugars in food into alcohol or acids. This process is used in a variety of different food products like beer, wine, and bread. During fermentation, the microorganisms convert the sugars in the food into ethanol (alcohol) or other organic acids as a way to produce energy. Yeast is the most common microorganism used in fermentation, but some bacteria, such as lactic acid bacteria, can also be used. The end product depends on what type of microorganisms are used. As the microorganism consumes the sugar, the food is preserved due to the acid created or the alcohol created. The alcohol content or acidity can be regulated depending on the desired product.