What's the Difference Between an Ale and a Lager?

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Join a conversation with your beer-aficionado friends and the vocabulary can quickly turn into a confusing flurry of styles, brewing methods, and microorganisms. You’ll probably hear the words “ale” and “lager” thrown around, nod approvingly, and silently wonder what the difference is.

It’s actually pretty simple. While lagers are known for their crisper, slightly more mellow flavor and ales tend to be fruitier, the separation has less to do with taste and more with how they are brewed. Ales utilize top-fermenting yeasts, usually S. cerevisiae, which interact with sugar near the top of the wort (the liquid product of boiling the barley and other grains) to produce alcohol at higher temperatures. Lagers ferment on the bottom of the wort and can take weeks or months to do their handiwork while chilling out at cooler temperatures.

The term “lager,” in fact, comes from the German word largern, or “to store.” Bavarian beermakers in the 15th and 16th centuries discovered lager when they left yeasts in cold storage for months at a time and noticed they were still fermenting—lager yeasts could withstand the near-freezing environments that made their ale counterparts go dormant. 

The variation in temperature produces different chemical reactions, which is why lagers tend to behave differently on the palate. While lagers are a relative newcomer to the beer scene—ales have been around for many, many hundreds of years—they have found favor with enthusiasts who enjoy their unique aroma and clean taste. Take a sip and find out for yourself.

There’s a lot to learn—and love—about your favorite brews. For more answers to questions about beer, including Guinness, check out mental floss’s Big Questions channel—preferably with a Guinness in hand. (But please remember to drink responsibly.)