After coffee, beer is Germany's favourite drink, but of course beer is still the national drink of Germany. There are over 1200 or so breweries in Germany and every town of a reasonable size has its own brewery.
Not all German beer is lager, whilst you are here you should try to taste as many as you can (responsibly). But be warned Germans can be very loyal to their local brew and ordering the wrong kind of beer in the wrong city can result in abuse and even violence, although this is not common, joking about it is.
The Reinheitsgebot is the 'German Beer Purity' law. It is a set of rules that started in 1516 and was set up to guarantee the quality of beer produced in Germany. However, it has also restricted the choice of beer produced in Germany. There are only a handful of different styles of beer available. There is an excellent web site all about the evils of the Reinheitsgebot here.
Altbier - literally means old beer - lovely old beer!
Especially associated with the area around the city of Düsseldorf and the Niederrhein, it is a traditional dark "ale".
Berliner Weisse - Berlin wheat beer - not to be confused with Weizen Bier / mit Schoss - with syrup!
My least favourite brew here in Germany. An acquired taste that requires the addition of syrup to make it palatible. It is naturally sour and vinegary, when ordering you may be asked "Rot oder grün?" - "Red or green?" This means do you want raspberry syrup or waldmeister syrup in it. Need I say more?
Bockbier - Bock is German for goat - even lovelier goat beer!!
Allegedly it originated in the north-German town of Einbeck.
There are different types of Bock beer. A traditional German bock is copper colored, but it can also be a dark brown (dunkeles bock). It has a full-bodied taste, with a slight malty sweetness. Bock can also be light coloured (helles bock).
Maibock is a bock with an extra measure of hops added near the end of the boil, to give it a pleasant hop aroma and flavor.
Doppelbock is an extra strength bock beer. It was originally invented by the monks around Munich. Since they couldn't eat solid food during Lent, they made this extra strong bock beer to give them the calories they needed to do their work. It's usually a dark brown in color, but can be paler.
Eisbock is a very strong version of Doppelbock. It's partially frozen, and the ice is removed to concentrate both the flavour and the alcohol.
Kölsch - a protected name (also the name of a TV police series here)
A speciality beer brewed in Cologne (Köln). Weaker and milder than Pils with a pleasant golden colour. Traditionally served in small glasses (Kölsch Stange) and carried on trugs.
Märzen - März is German for March
One of the oldest styles of beer. Traditionally amber or reddish-brown in colour Märzen beers were brewed in winter and then by March they would have to be kept (lagered) in cold caves (this was before the days of refrigeration), they would then be consumed around October.
Pils - this beer style belongs to the Czech area as Pilsner, but was adopted by Germany and shortened to Pils to avoid litigation
The taste of Pils varies from place to place. But it should be refreshing wherever you drink it. And it gives you the excuse of collecting the beermats or the labels off the bottles. Write a crib note on the back - liked it - didn't like it.
Schwarzbier - literally means black beer
This is the darkest beer I have found in Germany, it is almost treacly in taste.
Weizenbier - translates into wheat beer - that's a bit better! - Not to be confused with a Berliner Weisse.
Hefe Weizen - Some weizens are bottle-conditioned and contain some yeast sediment; accordingly, they are labeled as "mit hefe" ("with yeast") or as "hefe weizen." Be careful they can disagree with sensitive tummies.
Kristall Weizen - Sometimes called 'Weizenbier', 'Weissbier', 'ein Kristall' or 'eine Weisse'. This one is my personal favourite in the summer months. Cold and clear - serve with a slice of lemon.
If this has whetted your appetite check out The British Guide to German Beer site.
There is a distinct culture to how you should drink your beer too. Every type of beer has its own glass.
Becher - this means mug in English, but it is also what you traditionally serve Weizzenbier in
Krug - this means jug in English, but in the pub it is an earthenware or stoneware beer mug with a handle
Mass - a liter of beer usually made of glass and damned heavy to carry when it's full!
Pokal - like a fluted champagne glass - Pils is often served in these sometimes called a Tulpe (tulip).
Seidel - a glass version of the Krug
Stange - Means queue in English but in beer speak it is a small 0.2litre glass for serving Kölsch
Stein - Means stone in English this is traditionally a stoneware mug, featuring a lid with a pewter hinge. The use of the lid allegedly dates back to the Black Plague and was to prevent flies from dropping into your beer - quite right I say, make them buy their own!
Weizenbier or Weißbier - Used to serve wheat beer. The glass generally holds 0.5 litres with room for a head. It is much taller than a pint glass, with a narrow base that grows wider toward the top. (Thanks to Happycat for the reminder).