Historically, mashing systems have evolved largely as a result of the advantages or for that matter the disadvantages inherent in the available brewing ingredients: water, malt, and adjuncts. Mashing systems were conveniently grouped under three methods: infusion mashing, decoction mashing, and double-infusion mashing. Infusion mashing is used by British breweries in producing ales, decoction mashing is most commonly associated in the production of lagers in Germany, and double mash-infusion mashing is a system used by large North American brewers in the production of lagers. A fourth method, temperature-programmed ("Step") mashing is now very common too.
Click on the following topics for more information on mashing.