Almost everybody is familiar with traditional wine reductions, whereby wine is gently simmered to reduce it’s volume and concentrate its flavors, usually in the form of a sauce, and applied to everything from charcutrie to pastas, salads and even fish dishes. Lesser known to the culinary world is it’s more mysterious brother, the beer reduction, which can be even more flavorful and rewarding than wine reductions, if paired well and made right.Fortunately understanding beer reductions requires only a cursory knowledge of chemistry and cooking, so we’ll be pretty straight forward without using a bunch of big fancy schmancy words.
The main difference between reducing wine and beer using heat is that very hoppy beers (IPA’s, bitters, pale ales to name a few) will only get more bitter as they are boiled. This is because as the hop compounds are heated (Alpha Acids) they undergo a chemical change that makes them more soluble in water, since alpha acids are the primary contributor to bitterness from hops. Unless you are going for a very bitter reduction (there are appropriate occaisions) stay away from overly hoppy beers. A good rule of thumb is if you try the beer, and you can taste a pronounced bitterness, try to avoid using it for your reduction. Sweet stouts, milds, brown ales, scotch ales, German bocks, marzens and light lagers do very well in reductions because they tend to be sweeter and more robust in malt flavor than most styles and very conservative in hop usage. Aside from that, there are no real hard and fast rules for what to add or what to pair with. Try to use beers that will compliment, rather than contrast, the flavors of the dish you are preparing. But hey, it’s your kitchen, do what you like!