When it comes to beer, there are two main classifications: ale and lager. The difference between these two types of beer lies in the fermentation process. Ales are fermented with top-fermented yeast at warm temperatures (60° to 70° F), while lagers ferment with lower-fermented yeast at cold temperatures (35° to 50° F). The yeast used in ale and lager beers is from the species Saccharomyces cerevisiae and Saccharomyces pastorianus.
The hops used in each type of beer also differ, with lagers having a more delicate flavor due to the cold treatment process. As a result, lagers tend to have a lower alcohol content than ales. For the average beer drinker, the difference between an ale and a lager comes down to what the beer looks, smells and tastes like. While there are many differences between these two varieties, some lager yeasts can survive in the 60-65° F range and some ales can go through a cold conditioning stage, producing beers that transcend the differences between them.
Craft breweries tend to produce ale beers more often than lagers because of the time and storage requirements for making quality lagers. Lager yeast is more fragile and slower than ale yeast, so it cannot survive in environments with high alcohol content. By understanding the facets of the brewing process and the ingredients that affect the final product, you can better appreciate the differences between ale and lager beers. Whether you prefer one over the other is up to you, but knowing what makes them different can help you make an informed decision.