ferment

An operation or process that changes food by adding special helpers like yeast or bacteria causes fermentation.

Fermentation often happens when we make things like bread, cheese, and beer. We add those helpful microorganisms to the mixture and let it sit for a while. As they work their magic, they break down some of the ingredients and produce new flavors and textures. This process can take anywhere from a few hours to several days or even weeks, depending on what we're making.