The classification of beer is based on the yeast used (which is responsible for fermentation). There are two big families:

*High fermentation (top-fermenting yeast) like the Saccharomyces cerevisiae (and its strains) that prefers high temperatures and rises to the surface of the vat during the process of fermentation. The obtained beers are generically called ale.

*Low fermentation (bottom- fermenting yeast) like the Saccharomyces carlsbergensis (and its strains) that prefers lower temperatures and during the process settles to the bottom of the vat. The obtained beers are generically called lager (it comes from the German verb which means to preserve, in the case of beer “in a cool place”).

There is also a third category of beers produced through spontaneous fermentation called Lambic. The Lambic is an exclusive specialty of Brussels, and it’s a type of beer so different that some people consider it a part from the world of beers. It is a spontaneously fermented beer, in which in general we don’t inocule selected yeast, but we use what is present in the environment (air, structures, etc.).
This beer is so linked to the environment so that it can be produced only in certain restricted areas in Brussels. Actually, several yeasts and wild bacteria attend during its long fermentation; also the particular preparation and the long aging in wood have their influence.
The traditional Lambic has a rich and intense aroma (sometimes aggressive ) unmatched , and once in the mouth it is equally complex and always very acid. The “pure” lambic is still (without gas) , but it is most often blended with different vintages lambic, giving rise to the foamy Gueuze , or re-fermented in the presence of sour cherries from Schaerbeek to make Kriek.
Always based on spontaneously fermented beers such as Lambic, other types of Kriek are produced with fruits different from the traditional cherries (especially raspberries, but also blackcurrant, peaches, strawberries, etc.). It’s important to say that currently not every single Kriek beers is produced by spontaneous fermentation, but sometimes white or red -brown beers typical of West Flanders are used as a base.

*The Bitters: they are the base of the English style. Often amber (but also golden), average gradation rather low – often below 10 or even 9 degrees saccharometres , 3.5% alcohol – and almost always with a pronounced bitter fairly.
*The Mild: this style is more and more rare: these beers are even lighter than the Bitter , rather darker, tending to the sweetness, delicate but tasty despite the low alcohol content.
*The brown ale: (equally rare) they might be considered as a strongest version of the Mild.
*The winter ale: these and the Old ale beers are usually amber or darker, more sweet and less drinkable, suitable for the winter season or for more “thoughtful” drinking. The alcohol content is higher, although quite variable (for the British standards a beer at 5 % is already strong, but the old ale even stronger push towards the 7 , 8, 10 percent alcohol).
*The Barleywine: (lit. barley wine ) they are powerful beers (8-10 % alcohol, and even more), sometimes they are syrupy and caramelized, but rather hoppy bitterness balanced with the sweetness of the malt .
*The India Pale ale: (or IPA) they were originally (in 800s) produced in the UK for the export to the colonies , and they were characterized by a hoppy and bitter taste exceptional. The IPA are now rare in the UK, and generally they aren’t very “respectful” of the tradition.
*The blond ale: their style is not very traditional , but they are increasingly popular and we can consider them as “basic” style (they reach, however, exceptional levels with the Westvleteren Blond).
*The belgian pale ale: they are more traditional but less popular, they are similar to the English cousins, but with more character of yeast.
*The saison: they are well characterized: golden or amber, sometimes sour, spicy and well hopped.
*The trappist and abbey: these beers are well known but they don’t represent a style, but -in one sense- a designation of origin: indeed, the Trappists are quite different from each others- albeit with some common characteristic- but the designation is accurate and it entails that the beer is actually produced by or under the direct control of the monks.
*The double: or dubbel, they have a medium high alcohol level ( ie 7%), they are dark, dry but malty.
*The Tripel: (also trippel) or triple, instead they are blondes, even stronger ( 8-9 % and more), fruity and often relatively hoppy .
* Similar to the triple are the golden ale , equally strong, more or less, they are blondes too and even more drinkable and “treacherous”.
*The stout: they are high fermentation beers, characterized by a very dark color and a very marked roasting; generally, the alcohol is relatively low and the bitter taste is intense; the aroma of hops is rather moderate, dominated by the typical chocolate and coffee aroma.
*The dry stout: they fully reflect these features and they don’t have the slightest hint of sweetness. The most known stout is the Irish beer called Guinness.
*The rarest sweet stout: these beers, while maintaining colour and toasty notes , are less bitter and more sweet (from moderately to strongly).
*The oatmeal stout: (middle sweetness) These too they are not so popular, they are typically velvety thanks to the use of the oat flour .
*The Oyster stout: there are traces of the combination of stout and oyster since 1800, in some writings of Benjamin Disraeli . In 1929 there was the first use of the oysters in the production of beer, at first in New Zealand, later imitated also in London. Nowadays the term Oyster Stout can indicates or a stout brewed with a handful of oysters into the tanks, or simply a drink that is well accompanied by a plate of these shellfish.
*The porter: they can be considered a bit less intense type of stout.
Finally, the Imperial stout: they are strong , bitter, toasted and a little fruity.
*The pils: they represent the most classic style (the origin is Bohemian, the name comes from the town of Plzen) they are in the light lagers family and they are characterized by a light or gold colour, with a copious hopping and a bitter taste. The thousands of international imitations often are so far from the classic Czech, Bavarian or Rhenish pils.
*The Helles: they are typical Bavarian beers, less bitter and more malty.
The dortmunder: they are slightly stronger.
*The dunkel: they are brown and very sweet and malty.
The shwarz: (rare) they are darker and toasty, a kind of stout (more malty and less bitter) low fermentation.
*The rauch: (smoked beers) they are typical of the German city of Bamberg, they are produced using special smoked malts over beech wood or peat; the most famous and representative rauch beer is the Schlenkerla, from Bamberg, which claims medieval origins.
*The bock: they are generally rather high alcohol content (6.5 % – 7.5 %, but even more) with a light colour, and a malty taste just balanced by the hops.
*The doppelbock: they are dark , generally with high gradation ( 7-8 % typical), again with the malt in evidence and naturally with a more caramelized flavour.
*The dark doppelbock: these beers sold in the spring in Upper Bavaria have a name which ends in -ator, in honor of the original exemplar called Salvator, a beer brewed from Paulaner in Monaco of Bavaria.
*The altbier Düsseldorf: they have amber colour, they are not strong , malty and rather bitter.

Thanks to Barman Italia