Beer styles are divided into the two main groups of Ales and Lagers. While there are many differences between the two, the most important distinction is the flavor. Generally ales have more fruity, robust flavors than lagers while lagers can be more crisp and subtle. Ales are often referred to as being "top fermented" by the way they stay on top of the beer during primary fermentation and Lagers are referred to as "bottom fermented" because lager yeast tends to settle to the bottom and ferment.
Ales:
Most Ale styles originated with the brewing traditions of England, Ireland, and Scotland. The wonderfully complex beers of Belgium also originated and still are brewed as ales. Some beers of Belgium are fermented with wild yeast that is in the air and through many years of brewing, these wild unique yeasts of this area exist in the walls and other surfaces of the fermentation area as well as the vessels and agingbarrels. These beers are called "lambic" and are referred to as being spontaneously fermented. These lambic beers are typically tart and cidery in taste and often are then aged with different fruits, sometimes in used port barrels for additional complexity, to counter these flavors. The most common and popular fruits used are raspberries or "framboise" as they are called in Belgium. While most beers brewed in Germany are different lager styles, the Hefe-Weizen (unfiltered wheat) beers are fermented with ale yeasts unique to this style. Kolsch and Alt beers of Germany are also ale styles. Ales are fermented at basically room temperature in the range of 60 to 75 degrees F. Most ale yeasts will not ferment below these temperatures. Depending on style, strain, and fermentation temperature, most ales are finished beers in 2-4 weeks, with some stronger styles taking as long as a year to age out. They are normally aged at lower temperatures at the end of primary fermentation.
From light to dark, here are some broad categories of traditional ale styles:
Wheat ales are primarily very light in color and brewed with a portion of malted or unmalted wheat in addition to malted barley. They range from the very light "Belgian Wit" or white beers, which are typically flavored with orange peel and coriander, to cloudy German Hefe-Weizens and their darker cousins, "Dunkelweizen (Dunkel means dark in German). "American Style" wheat beers are fermented with more common ale yeast strains, typically the same strain used for other ales brewed at the same brewery, and do not exhibit the banana and clove flavors of the Hefe-Weizen or German and Belgian versions.
Pale Ales encompass a large variety of beers and can range in color from golden or blonde to copper and deep amber. In Britain they were called "pale" because they were lighter in color than the earlier brewed browns, porters and stouts. Likewise, Pale Ales can vary in hop character from the lightly hopped cream ales to the super hoppy India Pale Ales. In general, American craft-brewed pale ales tend to be lighter in color, drier, and hoppier than their English counterparts.
Bitters is an English term for a well-hopped ale, most often on draught. Although examples vary widely, the name implies a depth of hop bitterness and range in color from bronze to deep copper. Basic bitters usually have an alcohol content of around 3.75% to 4% abv (alcohol by volume). "Best or Special" bitters come in around 4 to 4.75%, and "Extra Special" (or ESB) about 5.5%
Amber or Red ale is a term coined by some of the new American craft brewers to denote a beer brewed with a higher percentage of caramel malts. These beers are often somewhat sweet or nutty and usually are not very hoppy.
German ales are often called "altbiers or alts". Alt is the German word for "old" and refers to the style of beers brewed prior to the discovery of lager yeasts. In addition to the amber to copper altbiers still found in Dusseldorf, there is a style known as "Kolsch", which is a blonde, delicately hopped ale found in the city of Cologne.
Brown Ales originating from England and the south of England are dark brown with a sweet palate and low in alcohol, about 3 to 3.5% abv. In the northeast of England they are a reddish-brown, drier, and 4 to 4.5% abv. Brown ales from American craft brewers are usually a little darker with more pronounced hop character than their English cousins.
Scottish Ales The ales of Scotland generally have a very malty profile. In their home country a single brewery's products may be identified in ascending order as "Light', "Heavy", and "Export or Strong". Or by a system based on the old currency of shillings, probably once a reference to tax ratings: 60/, 70/, 80/, 90/. Alcohol content in abv might rise through 3%, 4%, 4.5%, and 7-10%. The term "Scotch Ale" is sometimes used specifically to identify a very strong, often very dark, malt accented beer. In America, this style often is brewed as a winter warmer seasonal.
Belgian Ales. No other country offers such a wide variety of styles - from wild spontaneously fermented brews and fruit beers to spiced wit (white) wheat beers to Trappist beers still produced in monasteries. A number of American craft breweries are now producing their versions of "Belgian Style" beers, either as part of or as their entire portfolio.
Porter is a London style that nearly became extinct, though it has been revived both in England and America. It is a lighter-bodied companion to Stout. They can range from light brown to black and often have a chocolate profile from the use of darker roasted malts.
Stout is an extra dark, almost black ale made with highly roasted unmalted and malted barleys. They are subdivided into "dry"," sweet", and "Imperial".
Barley wine is an English term for an extra-strong ale (implied to be as potent as wine). They range in color from copper to tawny or dark brown with a 7-10% abv. The American versions are usually stronger and hoppier than their English counterparts.