What is the difference between just beer, ale, lager, and a stout?

Beer is the overall generic term for fermented malt beverages – whether it is an ale or a lager, it is still called beer! There are ONLY two kinds of beer – ales and lagers. Within those two broad categories there are many styles. Major ales styles are pale ale, IPA, porter, stout, and barleywine, just to name a few. Among the major lager styles are pilsner, Märzen, bock, and dunkles (dark lager). What really differentiates an ale from a lager is the temperature of fermentation. Ales ferment typically between 64 and 70 degrees F, and lagers ferment typically between 52 and 58 F. Fermentation is the process whereby yeast consumes the sugars from the malt, and in turn produces alcohol and carbon dioxide. All yeast strains, in addition to producing alcohol and CO2, also produce small amounts of other compounds which add subtle flavor complexity to the beer. With warmer fermentation temperatures (ales), yeast will produce elevated ester compounds. These come across on the palette as a ...  more