The first thing to settle right at the beginning, is that the title of this little article is completely misleading. The reality is, Ale is a type of Beer. The article should probably be titled Lager vs. Ale, but that doesn’t sound anywhere near as exciting, so for the sake of maintaining interest, we’ll stay use the term “Beer” to refer to Lager beers. You might quibble and ask, ‘What about Pilsner beers?’ but Pilsner is a type of Lager, so we’ll just stay with the original comparison between Beer and Ale.
The primary difference between Beer and Ale is the type of yeast used in the fermentation process. Ale, the earliest form of beer, is made with top-fermenting yeast, which is the most common form of the beneficial little fungi. S. cerevisiae is the most common yeast out there. It’s been around pretty much since the dawn of time, and you’ll find it all over the world. Folks use it for everything from winemaking to bread baking, and of course for fermenting grain to make – yep, Ale.
Top-fermenting yeast ferments throughout the body of the beer wort, rises to the top, then sinks to the bottom of the brewing vessel. This type of yeast has a high alcohol tolerance, and thus can be used to produce a drink with higher alcohol content.
Lager Beer, on the other hand, is made using bottom-fermenting yeast, typically Saccharomyces uvarum. This type of yeast isn’t quite as hearty as its top-fermenting cousin and is less alcohol tolerant. It ferments throughout the body of the beer wort then sinks to the bottom. It also has the unique ability to continue working at colder temperatures, resulting in a drink that is more mellow, more full-bodied, less hoppy and with a crisper taste than Ale.
Lager Beer typically takes around twice as long to ferment as Ale, but for most folks in the Middle Ages, when the lagering process was discovered, the results were well worth the wait.