Active Fermentation Dry Hop, pH, and the creep
We've started playing with some active fermentation dry hopping and have noticed a few things that I wanted to see if anyone else has seen or has experience with:
1) The dry hop creep, where your fermentation drags out towards the end, dropping .2-.1 a day for 5-7 days. We have tried dry hopping at different points of fermentation (day 2 of fermentation, half way through, with 1 plato left), but have seen this happen during each. Typically this is adding about 5 days onto fermentation before we are comfortable calling it "done." Not sure if this is due to decreased flocculation and therefore more contact with fermentables or if it is some type of interaction with glycosides. We use Wyeast 1056 and I'm leaning towards decreased flocculation, but curious about others experiences/information.
2) A steady increase in pH after the dry hop. Fermentation is steady and we don't see a big jump until the end, but we have seen beers that are fermenting at a stead 4.3 pH jump to 4.7 or 4.8 within a day or two. Yeast viability and vitality all look fine and we don't see this on anything other than our active fermentation dry hops. At 4.8 pH (the highest I've seen) the beer passed sensory, plates/pcr, and was well received, but from that jump I expect something to be wrong. Not sure if it is polyphenols or some type of yeast/hop interaction that is causing the pH to spike. Again, no off flavors or contamination to speak of, but its nerve-racking to see those numbers and, from what I understand, hydrolysis of hop oils happens better at a lower pH.
Any information or experiences of the like would be great. Thanks!