Hey folks, I brewed a Zombie Dust clone, all grain about 12 days ago. I used 2 pkgs of Lallemend London ESB for a 6.25gal batch. My OG was 1.070, with a target FG of 1.017. I fermented in as Ss Brewtech conical. The fermentation was robust, and arrived at 1.014 in 3 days. A little low, but nothing that worried me. I added 2oz of citra dry hops at about 1.020. Everything was great. For 7 days, up until day 10, the gravity level stayed at 1.014 and the beer tasted juicy, with bright citrus aroma. On day 10, I did a first dump to get rid of the trub and dry hops that had been in there for 7 days, and was planning to keg at 2 wks, to condition for a week before putting it on tap.
Unfortunately, on day 12, I took another sample and reading and the gravity dropped to 1.009 and the juiciness in the beer was totally gone, as was some, but not all, of the aroma. The beer doesn't taste 'off' in any way (no astringent or mediciney taste) but the fruitiness of the citra hops is largely gone and the beer is more bitter (I assume because it's dryer).
My question is why the gravity would drop like that (a full bric from 9 to 8 on my reflectometer) after having been stable for a week? Plus, this is not the first time this has happened to me, and with a range of different types of beers that may or may not have been dry hopped. Is it the agitation of the yeast when dumping the trub? Is it biotransformation, which I feel like if it was it should have happened sooner after adding the dry hops? I guess theoretically it could be an infection, but I don't taste anything obvious and after sitting for 7 days with a 7.2% abv, I feel like it's unlikely to develop at that point. Maybe my mash temp was off (reading off my bruzilla) but again, the gravity was stable for 7 days before it dropped again.
So I'm out of ideas. This beer was on track to be epic. Juicy, amazing aroma, soft bitterness...etc. Maybe it straightens itself back out again when it's cold and carbonated, but I don't even know if I'll get that far. Is it going to keep fermenting more now? Anyway, folks, please advise!