So a couple recent beers got me wondering about how breweries blend different beers to come up with a new beer—and whether the concept of "blending beers" is really even accurate. The Deschutes/Hair of the Dog Conflux No.1 (Collage) is a blend of Stoic, Dissident, Adam and Fred. What I'm wondering is, are they blending the wort used to make these four beers and then fermenting them? Or are they literally taking four fully fermented beers and somehow blending them and aging them together? On the label of The Bruery Fruet I picked up it says something like, every year they're taking some of the original 1st anniversary beer and blending it w/ other newer beer(s) to create a new anniversary beer (sorry, I don't have the bottle on hand to type the verbatim text). Do they mean the original wort that was somehow preserved is blended with new wort and then fermented? How do they prevent oxidation/degradation? Admittedly I don't know a ton about the brewing process other than homebrewing a few crappy batches of beer many years ago. I've just always wondered how this blending is done given all the issues re: sanitation requirements, exposure to air, etc. Cheers!
The general answer to your question...blending is a post-fermentation process. Though I am no expert, the majority of blending done by breweries is generally of barrel aged, sour, and/or spontaneously fermented beers. Given the unpredictable nature of barrels and the wild yeast (relied upon in spontaneous fermentation), blending is used to even out a batch for the desired product. Not only does this give the brewer/blender some control over a somewhat unpredictable process, but it ensures that all the bottles from a single batch contain the same products (rather than xx bottles from barrel 1 tasting different from xx bottles from barrel 2 and so on). In the case of Collage, the four contributing beers were blended after substantial barrel aging individually in a variety of barrel types. In this case, I would venture that an aim was complexity (and uniqueness). Based on my drinking one bottle so far, I consider that a mission accomplished.
Even as a homebrewer you can manage the sanitization (PBW and then StarSan... or PBW and then heat etc) and air exposure (you can co2 out the storage vessel, as co2 is heavier than o2) so you figure that if YOU could do it for a few hundred bucks in homebrew supplies, a major brewery is going to have that worked out just fine. Depending on the beer, it's possible for certain things to sit in barrels, kegs, or even bottles for a very long time under the right conditions. Wort is referring to the beer before fermentation--I believe blends are generally post fermentation... so blends are complete/finished beers (maybe things that would be consumed, maybe things that are designed to be parts of a whole, and wouldn't be enjoyable on their own) combined by the brewer with the purpose of creating Frankenstein's monster. Sometimes it works out great, and sometimes they're a mess.
The Bruery anniversary beer is a solera style blending method where they take fermented beer and blend it with last year's. They keep blending in the same barrels year after year to create an "average" of vintages. Oxidation can become a characteristic of any barrel aged beer, really. I suppose an infection can occur over time but with such a high ABV beer I don't see that happening very easily. Brewers/blenders will have a tasting session where they figure out the correct ratio for the beer they are trying to make. Then the beer is blended in that ratio. Sometimes poorer quality beer can be discarded. One of the few beers I've known to be blended before fermentation was the batch of Kabert they brewed at Portsmouth. Probably just because of space constraints for fermentation.
i'd be curious to see how two batches of wort blended together and fermented (assuming they use the same yeast) would turn out compared to fermenting the same batches separately and then blending.
Thanks for all the great answers, just what I was hoping for! This leads to a follow-up question, especially in the case of Conflux No.1. Do they brew entirely new batches of Stoic, Dissident, Adam and Fred specifically for this collaboration? Or do these breweries already have big stockpiles of these beers (particularly Stoic and Dissident, which are one-off or at best annual beers)?
