What’s the difference between an ale and a lager? To a brewer, it’s all in the yeast. But most beer drinkers choose their beer for the taste. Read on to learn more.

Beer-making is an ancient art. Evidence in Iran shows mankind has been brewing beer for at least 7,000 years. China, Mesopotamia (Iraq), Egypt and other locations also record ancient beer making.

When did we learn about yeast? For thousands of years, brewers (mostly women, by the way) made beer without knowing anything about yeast. Leeuwenhoeck first observed yeast in beer in 1680, but it took until 1857 for Pasteur to demonstrate the fermentation process.

Before yeast was understood, brewers knew their beer would be better if they reused the same vessel. They often collected the foam from the top of the kettle, unaware of their role in cultivating the yeast used in ales today.

Top fermenting yeast is used to brew ales. One of the few breweries still using open fermentation tanks is the Samuel Smith Brewery, in Tadcaster, England.

England and Ireland are known for their ales. Fullers brews a classic IPA, Guinness is well-known for its dry stout, and Innis & Gunn makes a classic Scottish Ale. Today, ales are made all over the world, including the United States.

“Lagering” beer. During the Middle Ages, Bavaria (now in southeastern Germany) and Bohemia (now in western Czech Republic) began using caves to store their beer during the warm months, often packing them with ice from nearby rivers. The German term for storing something away is “lager”.

The brewery of the original pilsner beer, Pilsner Urquell, still uses caves like this for some of their beers:

Bottom fermenting yeast is used to brew lagers. While being stored cold for the summer months, the fermentation slowed down and yeast settled to the bottom. Over the years, these brewers were unknowingly selecting for bottom fermenting yeast. In the 1820s and 1830s, Gabriel Sedlmayr, of Spaten Brewery, collected samples of fermenting beer from several European breweries. By the early 1840s, his son was brewing dark lagers, and the new method (plus the yeast) spread across Europe. In 1883, Emil Christian Hansen isolated a single strain of yeast.

Germany and the Czech Republic are known for their lagers. Spaten still makes their classic dunkel, Pilsner Urquell is the home of the original pilsner beer, and Paulaner makes the original doublebock. Today, lagers are made all over the world, with the pilsner style inspiring more beers than any other.

But, what about taste? Beer experts will tell you lagers have a “cleaner” taste, and ales often have fruity flavors, even when fruit is not added.

Of course, they’re right, but these differences are subtle when you look at the wide range of styles of each type.

• Lagers range from American light lagers to German doublebocks
• Ales range from English bitter ales to barleywines, and include stouts, Trappist ales and wheat beers
• An English bitter (ale) tastes more like a German helles (lager) than an English barleywine (ale) or a German doublebock (lager)

Ale or lager, there are many styles to choose from. Enjoy the journey.