Fermentable refers to something that can be broken down by microorganisms, such as yeast or bacteria, during a fermentation process. This typically involves breaking down carbohydrates into simpler sugars and other compounds through the action of enzymes produced by these microorganisms. Fermentable materials include various types of foods like fruits, vegetables, grains, and even some animal products such as milk or meat. During fermentation, these substances are converted into alcohol, lactic acid, acetic acid, carbon dioxide, and other byproducts that can impart unique flavors and textures to the final product.