ALL beer styles fall within two major categories- ales and lagers. Once you wrap your head around the notion that imperial stouts are considered ales, you’re in good shape. Ales have been documented for over 5,000 years now. Ales have yeast that ferments at the “top” of the fermentation vessel, and typically at higher temperatures than lager yeast. Depending on brewing style, ales can be enjoyed when they are young (couples weeks) or very old (couple of years). Here’s a run down on the ale styles and the mighty Pittsburgh breweries that showcase them!