Mashing is the brewing stage in which ground malt (grist) is mixed with hot water so that malt enzymes convert starch into fermentable sugars. Temperature-programmed rests favour different enzyme groups: β-amylase (60–65°C) for maltose and fermentability, α-amylase (70–75°C) for dextrins and body, proteases for free amino nitrogen, and β-glucanases for lautering — shaping wort composition, beer body, flavour and clarity. It is the key extract-yielding step of brewing, typically lasting 1–2 hours, followed by lautering to separate sweet wort from spent grains. Mash pH, liquor treatment (calcium levels) and grist fineness are controlled to optimise enzyme activity, and the process is fully documented in brewery QC.