The brewing process involves: 1. Malting Barley is malted to activate enzymes that break down starches into sugars. 2. Mashing The malted barley is mixed with hot water to extract these sugars, creating a wort. 3. Boiling The wort is boiled, often with hops for flavor and preservation. 4. Fermentation Yeast is added to the cooled wort to ferment the sugars into alcohol and carbon dioxide. Barley is the essential grain that provides the fermentable sugars for beer.