What role does yeast play in the brewing process?

Yeast is a crucial component in the brewing process primarily because it ferments sugars into alcohol. During fermentation, yeast consumes the sugars extracted from malted grains and converts them into ethanol (alcohol) and carbon dioxide through its metabolic processes. This transformation not only produces alcohol, which is essential for beer, but also contributes to the development of various flavor compounds and aromas, influencing the final profile of the beer.

While yeast does have indirect effects on other aspects of beer, such as contributing to flavor complexities and aromas through byproducts of fermentation, its primary and indispensable role is the conversion of sugars to alcohol. Understanding this fundamental role highlights why yeast is often referred to as the metabolic workhorse of fermentation in brewing.