Mashing
Brewers soak malt, usually made from barley, in warm water to extract sugar. This is mashing.
Malt is made by encouraging grains to start germinating before heating them to stop further growth. Malting produces enzymes capable of converting starch (inside the grain) into sugar.
Normally this conversion fuels the plant’s growth, but brewers use it to create sugary wort for fermentation into beer.
There are two types of starch in malted barley: amylose and amylopectin.