Venture CaféYour deepest and darkest questions about alcoholic beverages: Answered.
The past two weeks at Venture Cafe, our taps featured Cisco Whale’s Tale Pale Ale, an English Ale, and Cape Ann’s Fisherman’s Brew, an American Lager. Guests noticed that the brews poured the same amber color, and they tasted similar enough that many asked me about the differences between an ale and a lager. Dutifully, I performed diligent research into the depths of (basic) beer knowledge to find the answer.
The ale originated in Britain, where craftsmen brewed the beer at room temperature, between 64 and 70 degrees. The top-fermenting yeasts that successfully ferment the brew at room temperature break down the sugars from the malts into elevated ester compounds, which give ales their characteristic fruity, complex taste. Additionally , the Brits added more hops and malt than their German brothers, which give the ale its more bitter and nutty taste.
Those German craftsmen, on the other hand, preferred their beer crisp and cool, so they fermented it in cool Bavarian caves, between 52 and 58 degrees. The bottom-fermenting yeasts that work under these cooler conditions produce fewer esters, but also produce elevated sulfur compounds that require cold storage (“lagering”) before becoming appropriately integrated into the beer. The Germans could reuse the yeast to ferment a new batch, so lagers tended to be more economical beers than ales.
So there you have it: the short version of the story, at least!
The top- and bottom-fermenting terms are a bit of an oversimplification. Lager yeasts are a lot slower growing and take a lot longer to proliferate. The term bottom fermenting really means that some lager yeast falls out of solution giving it the appearance that it’s going from the bottom up even though there are millions of yeast in suspension. The cool temperatures lagers are fermented at also help to reduce any potential bacterial or other undesired contamination during the (really long) fermentation process. With Ales that’s not a concern because rapid fermentation and yeast proliferation begins immediately once the yeasts hit sugar and is almost over before you know it.