At this stage, the malt is mixed with water and heated at specific temperatures for a set period of time, allowing the enzymes to convert starch into fermentable sugars. This conversion of starch into simpler sugars is called saccharification.

There are three main mashing methods. The first is infusion mashing, which takes place at a single fixed temperature. The second is step infusion mashing, during which the temperature is increased once or twice. The third is decoction mashing, in which part of the mash is removed, boiled, and then returned to the mash tun. This final method is traditionally used for producing Lager-style beers.

In decoction mashing, the malt-water mixture is initially heated to 50°C, activating the malt’s proteolytic and cytolytic enzymes. Proteolysis is essential for breaking down proteins into amino acids that yeast will later consume for growth. Cytolysis improves the efficiency of the subsequent filtration process. At the same time, part of the mash is removed and boiled. After 10 to 60 minutes, the temperature of the main mash is raised by reintroducing the heated portion. The mixture is then held at the achieved temperature for another 10 to 60 minutes.

The temperature is then increased again to 75°C. At this stage, the starch-degrading enzymes α-amylase and β-amylase become active. These enzymes hydrolyze starch into fermentable sugars. Once the desired enzymatic activity has been completed, the mash is heated one final time to 75–77°C, causing the enzymes to become inactive.

The mash is then transferred to a vessel for filtration, where the liquid wort is separated from the insoluble malt solids. The remaining solids are used as animal feed. Filtration must be carried out quickly to avoid the extraction of tannins from the husks and unwanted darkening caused by oxidation.