Ales
This category of beer uses yeast that ferments at the “top” of the fermentation vessel, and typically at higher temperatures than lager yeast (60°-75°F), which, as a result, makes for a quicker fermentation period (7-8 days, or even less). Ale yeast are known to produce by-products called esters, which are “flowery” and “fruity” aromas ranging, but not limited to apple, pear, pineapple, grass, hay, plum, and prune.
Lagers
The word lager comes from the German wordlagern which means, “to store”. A perfect description as lagers are brewed with bottom fermenting yeast that work slowly at around 34 degrees F, and are often further stored at cool temperature to mature. Lager yeast produce fewer by-product characters than ale yeast which allows for other flavors to pull through, such as hops.
Hybrids
Hybrid beers are those that don’t fit neatly into either the ale or lager category. There are relatively few examples of them. The difference usually lies in the unique technique used to brew them. California common, for instance, is brewed with a lager or bottom fermenting yeast but it is fermented at an unusually high temperature for lagers. Hybrids are typically dry like lagers but retain malty flavors.
