0800, Thu 8 Dec
The airlock has been hissing loudly since fermentation started about 14 – 18 hours after pitching, and although the graph hasn’t flattened out completely I see that the surface of the brew is completely clear, and all yeast has disappeared apart from the usual remnants of dried Krausen around the rim.
So what to do now? I’d like the finishing hops to go in there before fermentation is 100% done so that we get a little bit of CO2 driving out any of the inevitably introduced oxygen, and with that curve not levelled out yet (at 66% attenuation, ostensibly) I think we have another day or two, but where’s the yeast? Was I right to under-pitch. Maybe I’ll wait until this afternoon before making a decision.
16:00, Thu 8 Dec
I checked the fermentation curve again this afternoon and it does indeed appear to have flat-lined, so I threw in the finishing hops and deployed the sanitised floating dip-tube. No purging or undue ceremony, hopefully there’s still a bit of activity in there to drive out the oxygen that I’ve undoubtedly introduced.