Mash

Mashing is the process of soaking crushed malted grain in hot water so natural enzymes in the malt break down starches into simple sugars the yeast can later ferment. It is the defining step of all-grain brewing, done in an insulated mash tun or a bag inside the brew kettle, and it typically holds a steady temperature range for roughly 60 minutes.

The exact temperature you hold matters because different enzymes are active at different points in that range: lower temperatures favor more fermentable sugars and a drier beer, while higher temperatures leave more unfermentable sugars behind for a fuller body. After the rest, grain is rinsed, or sparged, to pull the remaining sugars out and leave behind mostly spent husks, and the resulting sweet liquid is your wort.

Grain milling matters here, since crush that is too coarse leaves sugar locked in the grain, while crush that is too fine can turn a mash into a stuck, slow-draining mess. A frequent beginner mistake is letting mash temperature drift too high or too low without checking it partway through, which changes the final beer's body and sweetness. A brewing thermometer or built-in temperature probe makes it far easier to hold the target range consistently.