This comes as a surprise to most people. "But what," they say, "about all of those porters, stouts, pales, pilsners, Flemish reds and Belgian Whites? What about all those acronyms - the IPAs and the ESBs, the IRSes or RISes (but notably not RUSes)?" This is one of the rare occasions where a basic wine comparison is informative rather than confusing. Just as Vigonier and Cabernet Franc fall neatly under the umbrellas of "White" and "Red" respectively, so do all of those beer styles you've heard mentioned fall under the aegis of either ale or lager.
"This is all well and good," I hear you saying, gentle reader, "but what the hell does that mean? The taxonomy of the tartaric and the tannic is tautological - what logic allies itself to ale and lager?" Well I'm glad you asked.
Ales:The first beers brewed were accidental ales. In a barrel of sweet barley water yeast set to work, a pleasant accident still familiar to us in the form of sourdough bread. These ambient, airborne, naturally occurring yeasts are the same ones that to this day create the true and traditional lambics. Over time, brewers bred for particular characteristics and developed strains and sub-strains specific to a beer, brewery, or brewer.
Ale yeasts are sub-species of the yeast Saccharomyces cerevisiae, also known as "Brewer's Yeast." It typically does its business on top of the fermentation vessel, and always for shorter periods and at higher temperatures than its cousin lager; the result is typically but by no means always stronger in flavor, less translucent, and higher in alcohol. Ales cover a wider range of the flavor spectrum than lagers, and include pretty much everything you drink that isn't a pilsner.
Lagers:
Down in the caves of Germany brewers used to hide their fermenting barrels to protect them from the spoiling heat of the central European summer - before refrigeration this was the only effective protection from runaway fermentation that would turn any brew to vinegar long before it could be served. But while their backs were turned trying to figure out if they had really been turning ontologial wine into doxologial blood, the Germans' Saccharomyces cerevisiae mutated into an equally real Saccharomyces pastorianus.
Lager is the German word for "store," or "to store." Pastorianus yeast typically ferments on the bottom of its vessel, and always at lower temperatures and for longer periods than its cousin. For reasons involving words like "phenols" and "esters" this leads to flavors that are most easily described as "clean." Lager includes the wonderfully refreshing and bready Stiegl and Weihenstephaner Original, which are both clear sparkling golden brews that leave little to be desired. It also includes opaque Schwarzbiers (blackbeers) and beef-jerky Rauchbiers (smokebeers). And Budweiser. And that's it! A short intro that is both exhaustive and a survey. Ales and lagers run the gamut, and beyond that there are trends, but not rules, about color, style, strength, origin, and flavor. We'll explore them further in future Backgrounds.
