Topic: Brewing beers like those you buy

[beachbum]

Decoction mashing is and old German technique where they take some of the wet malted grain out of the mash, bring it to the boil in a separate pan and tip it back into the mash to raise its temperature. They do this two or three times until the mashing (conversion of the starches) is complete - takes a couple of hours.

Nowadays modern malts don't need decoction mashing unless you are really looking to duplicate a "high end" lager such as Pilsner Urquell. Most German breweries just do simple mashes and heat the mash in temperature steps by other means to emulate the old decoction method.

At home you can make a very drinkable lager by just a single step mash at around 64? using pale malt, then boil the 'runnings' with continental hops available from most home brew suppliers. Then ferment very cool using a lager yeast.

DMS is dimethyl sulphide which can be a by product of using true lager malts. It smells like creamed corn and you can pick it in some brews like Carling. Continental breweries boil the "wort" for 90 minutes to 2 hours (longer than a boil at an ale brewery) to boil off the DMS which can be objectionable at high levels, but it's still a signature of many lagers and adds to the complex aroma.