If you ask what the difference is between ales and lagers, you will get different responses depending on whom you ask.

If you ask beer drinkers, they might tell you that in general, ales have more complex taste, are often more bitter than lagers, and are more aromatic. Lagers are lighter, have more carbonation, and have a cleaner taste and aroma. Further, whereas lagers taste better served cold (roughly 35 to 45 degrees Fahrenheit), ales are best served warmer (roughly 45 to 55 degrees, and sometimes warmer).

However, because beers that fall into each category vary widely, blanket statements about ales or lagers are often not helpful, and sometimes not even correct. This is where the brewing perspective comes in. Brewers will tell you that the primary difference between ales and lagers is the type of yeast used in the fermentation process.

Ale yeast generally ferments between 55 and 70 degrees Fahrenheit, and lager yeast generally ferments between 38 and 50 degrees. Because of the lower temperatures, lager yeast also ferments more slowly. This aging makes lagers a little more mellow than ales. Also, the lager’s colder temperatures are not conducive to the production of some of the fruitier aromas that are evident in ales. This explains why we can generally say that lagers are cleaner and less complex than ales.

Another thing that brewers will tell you is that ales are top-fermenting and lagers are bottom-fermenting. That is, ale yeast rises to the surface of the fermenting beer, whereas lager yeast will settle on the bottom during fermentation.

But again, if you are asking as a beer drinker, some of these finer details are unimportant. What is important is what you like, and to a lesser extent, the general characteristics of ales and lagers mentioned above. It doesn’t hurt to keep these guidelines in mind when trying a new beer, but there is more than enough variety within each of the two categories that it is worth trying as many of each as you can. The beer world is full of surprises.