The main ingredient used to brew beer is malted barley, although other grains can also be used. During the brewing process, the sugars from the malted barley are converted into alcohol through fermentation, aided by yeast. The grains are first mashed in hot water to extract these sugars, which are then boiled with hops for flavor and aroma. The choice of grains, hops, and additional ingredients significantly influences the taste, color, and aroma of the final product, resulting in a vast diversity of beer styles available worldwide.