I have a 5 gal batch of CS extract currently in primary. Noticeably active fermentation lasted about 36 hours, used blowoff tube but lost very little through the tube. Pitched at 54F, fermenting beer temp never got above 64F (swamp cooler). During 3rd day in primary things calmed down, krausen fell, everything looking good so I was set to just leave it in primary for three weeks, then test SG and bottle. But 2 weeks and two days into primary, started getting airlock activity, a good bubble every 5 seconds or so. This lasted for about a day and a half. Towards the end of this activity I took a gravity reading–1.018. OG was 1.042. Tasted the sample and all the good flavors were there except there was a faint hint of sour milk/baby spit up. Is this diacetyl? If it is, I’m figuring that leaving it alone for another week or so might help?
Also, just after this last round of airlock activity, a thin (about 3/8 inch) layer of krausen has formed-uniformly covers the beer and looks like the head on a good glass of beer. This just all seems a little strange to me. My first CS was brewed at way too high temps, and I had no discernable off flavors. This one I was obsessive about ferm temps, and seem to have some problems. Used the default yeast(danstar windsor ale-rehydrated per instructions).
Am I worrying over nothing, or does anybody see a problem? (other than my inexperience)
Thanks,
Ron
