Wow. This is crazy! Although I’m pretty sure I’ve read that it has something to do with the color of the beer too.
Contrary to a weirdly held popular belief, the color or clarity of a beer has nothing to do with its ale or lager classification. There are blonde ales that are as pale as classic Czech pilsners (a lager), and smooth, dark lagers like schwarzbiers that are as opaque and jet black as stouts (an ale). That’s because color in beer is imparted by the malt bill (and in the case of certain recipes, additives like fruits, spices, and other random ingredients), and has nothing to do with the yeast being used.
...OK, so then if that’s not the case, it’s definitely the alcohol content! My friends tell me that lagers are way lighter.
Sorry, but your friends are lying to you. Unless you consider a 9.5% ABV doppelbock a “low-alcohol beer,” lagers can sometimes make up the strongest beers being offered on a menu.
Ugh. So then at least they should taste different?
In so many cases, yes! Ale yeasts produce more esters and phenols during fermentation, which are the byproducts that give beer those non-hop, non-malt driven flavors. If you’re wondering what that means, think about the last time you had a spicy, fruity Belgian ale that smelled of cloves and pepper, or a German hefeweizen that tasted like ripe banana and bubblegum, or an English ale that had perfumey, floral stewed fruit flavors. This is in stark contrast from the clean, crisp, rounded flavors and aromas of beer fermented with lager yeast.
Are there any exceptions to this rule?
With beer, there are always exceptions to the rule. Some pretty famous styles can be considered hybrids of the two. Kölsch and altbier, for example, are made using ale yeast that is fermented at lager temperatures. California common lager (or “steam beer,” if you’re down with the proprietary name that was copyrighted by Anchor Brewing Company) is an American-born style that involves lager yeast brewed at ale temperatures. This middle ground can be a pretty friendly place if you know what you’re doing. Kind of a best of both worlds situation!
So what are some popular examples of each type?
Lagers have a history that has deep German and Bavarian roots, so it can help to think of an area when trying to remember the categories. Besides that, pilsners, adjunct lagers (think big brewery beers made with lots of rice and corn), schwarzbiers, bock, doppelbock, and Vienna lagers are all prime examples. Ales are more traditionally linked with Belgium and Great Britain, so think IPAs, stouts, pale ales, brown ales, saisons, dubbels, tripels, and quads. Of course, the world is a small place these days and you can brew a saison as easily in Phoenix as you can Flanders, so never make assumptions just because of where a beer is coming from.
This seems so basic. Why is it so hard to understand?
The point is the distinction is important only to get a better understanding of what you already like. So please don’t beat yourself up over this. Even well-intentioned food journalists often make this mistake! Now take this as an excuse to go hit up your favorite local beer bar or shop and do some homework.