Beer Science: What’s The Difference Between An Ale And A Lager?

By 03.05.17

Are you looking to drop some knowledge on your hungover friends at brunch today? Look no further my friends. There are two types of beers: ales and lagers. Despite different variations such as pilsners, stouts, dark, amber, blonde, malts, they all fall under either an ale or a lager. So what’s the difference? It’s science.

It all comes down to how the beer is brewed to determine if it is an ale or a lager, and has nothing to do with taste, alcohol content, or color. All beer starts out with your basic four ingredients: grain, hops, yeast, and water. The difference between ales and lager is the yeast and temperature.

Ales are “top fermenting,” meaning during fermentation the yeast interacts with sugar near the top of the wort (the liquid extracted from the mashing process during the brewing of beer) to produce alcohol at higher temperatures, in the range of 68° to 72° F. Ales use top-fermenting yeasts, which is usually saccharomyces cerevisiae. The yeast actually rises to the top of the tank near the end of the fermentation process. Ale yeasts will produce chemicals called esters that can affect the flavor of the beer.

Meanwhile, lager is “bottom fermenting,” where fermentation takes place at the bottom of the wort at cooler temperatures, around 45° to 55° F. Lagers use a yeast called “saccharomyces pastorianus.” Lagers take longer to mature because of the cold temperatures, which are usually made in cold storage. That is why it is called “lager,” which comes from the German word “largern,” which means “to store.” In the early days, they were stored in a warehouse where it was cool. Lagers tend to have lower alcohol content due to the yeast’s lower alcohol tolerance. Lagers are new, relative in brewing terms. They were first seen in Bavarian breweries in the late 15th or early 16th century.

However, there are exceptions. There are rare cases where brewers use “bottom-fermenting” yeasts to make ales.

Lagers include pilsners, bock, and dunkel and are brands such as Budweiser, Heineken, and, Sapporo. Whereas amber, IPA, porter, stout, and Belgian trippel are ales.

So there you have it, go impress your friends with your new knowledge as you down an ale or a lager.



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