When brewing an all-grain beer, you need to decide on a mash method. If you are following a recipe, the mash details are likely spelled out for you. However, if you’ve drawn up your own recipe — or are using an existing recipe and want to pick the best mash method for it — you should know how to choose a mash method.
Many homebrewers will choose their mash method based on the style of beer they are brewing — a single infusion mash for an English ale, a decoction mash for a German lager, or one of the slew of different mash methods used in traditional Belgian brewing for brewing a Belgian beer. (You will also need to decide on a lautering method — of which continuous sparging, batch sparging, and the no-sparge, brew-in-a-bag (BIAB) method are three popular choices for homebrewers. But that’s another topic.)
Practical homebrewers should understand that mashing is an extension of malting and the vast majority of malts produced today are intended to be single infusion mashed. These malts are called fully-modified. Unless your malt is labelled otherwise, any base malt you buy is overwhelmingly likely to be fully modified.