I'm supposed to chat with some homebrewers tonight, and I've been thinking of why "style" fails, and I think it's because it captures only one dimension in what should be a more complex taxonomy. Forthwith, I'd like to offer a new structure, with examples. When thinking about what makes a category of beer worth carving out from the herd, it's useful to consider not only style, but brewing method and regional tradition. Take saison and biere de garde, often lumped together as "farmhouse ales." Speaking as a matter of regional tradition, this makes all kinds of sense--they come from a single source. But in terms of style, it's absurd; biere de gardes have evolved into something closer to lagers, while saisons have clung to their rusticity.
- Method. Some categories of beer are distinctive because of the way they're brewed. British and American ales are often constructed identically in the brewhouse, but when the former are pulled from fermenters a shade before terminal gravity and packaged in casks, they become quite different from the latter, force-carbonated in kegs. Similarly, Belgians make tons of beers designed to go through a secondary fermentation in the bottle.
- Tradition. The best example here is the (tiny) group of beers people have called oud bruins, Flanders brown, Flemish red, or (the worst) Flemish red/brown ales. The beers don't really share a style, and they certainly don't share a method, but the reason people try to group them is because they do share a tradition. Until the past few decades, brown ales were the standard in Flanders, though every brewery had a different method of producing them. As they have slowly died out, we're left with a disparate collection that don't look or taste a hell of a lot like each other. Yet it still makes sense to group them together because of their shared regional tradition.
- Style. For the most part, styles are an effective framework. When we say kolsch or cream ale, we know what we're getting. Styles have been built on the chassis of method and tradition, and are usually decent enough proxies.