All beer can be classified as either a lager or an ale. The differences begin during the brewing process. Whether the beer is an ale or lager is defined by the type of yeast used in the brew and the temperature at which fermentation takes place. Ales are brewed with top-fermenting yeast which allows for rapid fermentation at warmer temperatures; Lagers are brewed with bottom-fermenting yeast which ferments more slowly and at colder temperatures. Lagers - Lager means to store or put aside. - This beer is made with bottom yeast, so-called because it flocculates to the bottom of the vat. - Traditionally bottom yeast will ferment at cold temperatures less than 10 deg C. Now fermentation takes place at 12 to 18 deg C. This cold or deep fermentation allows the malt and hops to assert their fine flavours. - Lager tends to be paler, drier and less alcoholic than ales. - Pilsener or pils beer originated in Bohemia where brewers first found beer that was over-wintered or lagered improved if stored in cool caves and kept on ice. - German lagers, including beers such as bock and marzen, are made according to the Bavarian Purity Laws of 1516 to ensure the beer is all-malt (no sugar) and hopped with bitter and aromatic varieties (noble hops). - Some German-style beers are described as "helles" meaning pale or blonde. Pale beers grew in popularity following the adoption of the glass for drinking in the 19th Century. Ales - Ales are brewed with top-fermenting yeasts at temperatures from 15 to 25 deg C. - Ales are matured for shorter periods and at warmer temperatures. - Ales include a wide range of beer styles from porters and stouts (porter is a heavy beer of pronounced bitterness, reddish-brown to a very dark brown, but is usually lighter in body and malt character than stout) to pale ales and wheat beer. - Generally, ales are higher in alcohol, more robust and complex than lagers.

Ale: An ale is a beer that uses ale yeast. Ale yeast is a top fermenting yeast that requires warmer temperatures. Ales tend to have a fuller body. Lager: A lager is a beer that uses lager yeast. Lager yeast are a bottom fermenting yeast that require cooler temperatures. While most modern lagers are fermented in large refrigerated rooms, in the old days they used to use caves. Lagers tend to have a crisper/cleaner taste. A stout is an ale, and is very similar to a porter. Both are dark due to the dark roasting of the grains. Stouts and porters are so close that some companies call their stouts porters, while others call their porters stouts. Basically a porter uses just roasted malt while a stout uses roasted malt and roasted barley. A pilsner is a light stout. Most light American beers are pilsners. They gained popularity because they were light enough to be enjoyed after a long hot day at work. They were a great alternative to drinking a heavy beer. A cream stout is a stout that has had lactose added to it for sweetness. If you added other sweeteners like sugar or honey the yeast would simply convert that into alchol. Yeast cannot convert lactose into alcohol, so the sweetness remains. An IPA (India Pale Ale) is an ale created by the British. Regular beer would spoil on the 6 month trip to India, so brewers created a beer with more alcohol and more hops, each of which helped to preserve the beer on the long hot journey. Steam beer is a beer that uses lager yeast, but at warmer temperatures. Old San Francisco brewers lacked refrigeration and caves so they were forced to make their lagers in warm temperatures, resulting in steam beer. A wheat beer uses wheat malt. A mead isn't a beer, but is one of the earliest alcoholic beverages. A mead is basically water, yeast, honey, and maybe some fruit juice. There's no cooking, you just let it sit and ferment.