Stan H’s newest excellent hop e-newsletter has a reference to a hop research study that Allagash Brewing and Oregon State University presented at the 2017 Craft Brewers Conference. Came as a surprise to read. Heavy dry hoppers who also bottle condition should read. Pretty interesting:
“With the increasing trend of greater dry-hopping rates, the impact hop compounds have on beer flavor and beer quality becomes more important, but it is not entirely understood. Experiments carried out at OSU suggest that residual enzymatic power of hops can be transferred to dry-hopped beer and, in turn, influence the composition of its fermentable and nonfermentable carbohydrates.” And, here’s one reason why such research is important: “The residual enzymatic activity of hops in beers containing active yeast may result in excessive build-up of CO2 in packaged beer, which represents a safety hazard, along with alcohol contents that are out of specification.” Brewers are in the results because such residual activity may create diacetyl in dry hopped beers."
Interesting. I remember reading old British texts that specifically cite amylase helping to further secondary fermentation and reduce residual sugars as a major reason for dry hopping. I always figured they were just talking buncombe.
I haven’t bottle conditioned much for a long time. I dry keg hop IPAs fairly heavily (5 oz-ish) and haven’t noticed much in terms of the beer getting progressively drier. OTOH these beers are best consumed young and often don’t last more than a month. But they sometimes last 2+ months and I still can’t say I’ve experienced it in a noticeable way. Anybody else? Maybe the effect seems noticeable quicker in the smaller volume of a bottle? Just thinking out loud.
Interesting. Not observing the drying out affect could also be due to the keg being kept cold limiting the amount of enzyme activity vs. a bottle which may be stored warmer especially during the conditioning phase.