Reminder : Ales are fermented by yeasts that float on top of the liquid, lagers (beers) are fermented more slowly by yeasts that sit at the bottom.

Germany

Helles and Pilsner beers
There are many excellent lagered, beers ie stored and conditioned for a long time, unfortunately not in the UK, Poland or Spain. The germans and the Czechs brew the best , with some good ones in Holland. However, most Belgian pils are extremely poor and they should stick to what they do best, brewing ale.

The germans brew many variants of either lagered, or pils beer. The main style in Bavaria is Helles style, elsewhere pils dominates.  In Franconia Helles beers are called Volbier. Other german beers include Dunkel (dark beer), Keller bier, Marzen (spring ale), Spezial (basic "bitter"), Bock and Doppelbock

Rausch beer
Or smoked beer, only found in Franconia,. The malted barley is heavily smoked before being brewed and the resulting dark beer tastes slightly burnt. The two main breweries of thiss style are both based in Bamberg. Schenkerla is the most famous and is a world classic beer. One of my most treasured memories is drinking a freshly tapped barrel in the brewery itself. The other brewery is the Spezial brewery which is not as distinctive as the Schenkerla, but the brewery tap has a wonderful welcoming local's atmosphere. Sadly the future of this brewery is in doubt as the premises were recently put up for sale.

Kolsch
A style of beer brewed in and around cologne. Although it looks like a pilsner beer, it is in fact an ale.

Alt beer
A Speciality beer from Dusseldorf. Dark and hoppy with a malty flavour

Belgian

Trappist
In order to be called "Trappist" the beers of the brewery must be made in a brewery controlled and occupied by Benedictine monks. Therefore trappist is not so much as style as  an appellation of origin, however they all share a similarity in terms of strength and fullness of flavour. There are six such  breweries; Westmalle, Westvleteren, Chimay, Orval, Rochefort and Achtel.

Five of the six each brew 3 beers, singel, dubbel and trippel, Orval being the exception with just one. It is believed that the origin in the difference is that singel was for normal monks and novices, dubbel for senior monks and trippel was reserved for the abbot.

As an aside there are also beers called Abbaye, which are brewed as copies in terms of strength and fullness of flavour, but whilst these can be perfectly palatable, they should be regarded as a separate group of beers.

Sour Brown Ale
These come from the East Flanders area of Belgium. They use Vienna malts (medium roast, rich aromatic) and are closely associated with the town of Oudenaarde, they are unusually brewed n that they are simmered overnight rather than boiled and then fermented in open vats for 6 weeks before being stored in vats for nine months or so. The best known is Liefmans Gouldenbande.  Whilst I respect this style as authentic, it is a taste I have never acquired due to their residual sweetness.

Sour Red Ale
Similar to sour brown ale, but from West Flanders

Lambic
Lambic is a style of beer that dates from before 13th century and is only brewed in or around Brussels. It is a catch all phrase to cover the collection of beers of similar brewing style that include gueze, kriek, framboise, faro and lambic itself.

The difference is how the beer is brewed. Firstly they don't use malted, ie roasted barley, rather it is raw wheat and barley mix. This is mixed gradually with boiling water which is then kept on the go for at least 3 hours with old hops being added to the mix. These hops have lost the "bittering" characteristic, the peppery tang at the back of the throat, but retain their antiseptic property. This is important as the beers are then fermented with wild yeasts in shallow tanks which are left exposed to the open air. When this process is complete the beer will be pumped into oak barrels and left for THREE years.

Gueze beer is a beer that is a blend of variously aged lambics which are specially selected to retain a consistent flavour. The best known are Cantillion and Drie fonteinen. The result is an incredibly complex beer, sharp, tart and sour. If elft for a few years the beer becomes more rounded and loses some of its assertive sourness. A taste genuinely worth acquiring, but be warned, the intial impression will take the unwary by surprise. It has NOT gone off.

Faro beers are young blended lambics which are sweetened with caramel to produce a sweet and sour taste. I've met people who like them but it's not my thing.

Kriek and Framboise beers are produced by adding young-ish lambic beers to a vat of cherries or raspberries and leaving it to condition for a few months. Be warned tho' that some breweries are adding fruit cordials to normal or slightly sour beers, these are not even remotely as good as the real thing.

Saison
A little known beer from the Wallonian part of Belgium that seems to be growing in popularity. Originally a summer beer brewed in spring and then stuffed full of hops to survive until the summer. It would be the equivalent of an English IPA.

Other styles.
Belgium is a country with a lot of different beer styles, many of which are obscure and only produced in small quantities. So it is difficult to summarise the variety of Belgian beer.  

Weisse, white, wit beer. (German and Belgian)

There are two main styles of wheat beer. The Belgian and the German where the Belgian are lighter and softer with a less pronounced carbonation. German wheat beers also have a tendency to use more barley in the mix and will also have dark wheat beers as well.

German wheat beers had almost died out by the 80s, when they were discovered by British real Ale enthusiasts who started raving about them and featuring them in British beer festivals. This alerted the Germans to the fact that they were on the verge of losing an important beer tradition and interest in them was revived.

However, Belgian wheat beers really had died out, back in the 60s. However an enterprising brewer called Pieter Celis found a recipe for a wheat beer from a long defunct brewery and tried it out. The beer was an instant success and Hoegaarden was born; please do not believe any suggestion that the brewery has made this beer continuously since the middle ages.

With this commercial success other Belgian styles were revived and the belgian scene now has a lot of very good wheat beers, most of which are authentic recipes even if they weren't brewed for a long time.

Incidentally, Mr Celis sold up in the 60s and emigrated to Texas, where Celis White is now brewed, imo an improvement upon Hoegaarden.

Nb People who drink wheat beer with lemon are philistines who should be stoned to death.