A mash tun is a vessel used in the brewing process to convert starches from grains into fermentable sugars. Typically made of stainless steel or insulated materials, it maintains a specific temperature to facilitate the enzymatic breakdown of starches. This process is essential for producing the sugars needed for fermentation in beer production. During mashing, crushed grains, often from barley or wheat, are mixed with hot water in the mash tun. The heat activates enzymes, which convert the starches into sugars. After mashing, the liquid, known as wort, is separated from the solid grain husks and is then boiled before fermentation.