When the airlock didn’t start popping immediately after I transferred the wort to the fermenter yesterday I was a tiny bit worried, and put it down to me not having rehydrated the yeast before pitching it, choosing instead to follow the manufacturers instructions and just sprinkle it on top.
This morning there was already some airlock activity to be seen, and by 10:00 we had individual bubbles linking together to make foam. It’s now lunchtime and the foam could almost be called Krausen, as the top layer is getting darker and being broken apart by lighter layers beneath to form something vaguely like the crust on a tiger roll.
There’s plenty of activity inside too, with a kind of boiling turmoil swirling around small particles of solid matter. I’m also getting good separation between what looks like sugary fluff and the clear wort. When the liquid was added to the Fermzilla yesterday this fluffy stuff, which had already started to settle out in the kettle, was mixed up again in the FV but started to sink quickly, completely filling the collection jar and starting to settle on the conical sides. Well, today that seems to have changed again, and there’s only an inch or two settled in the collection jar and a small amount on the sides of the vessel. I don’t know if the yeast is circulating the rest or if it’s compressed down in volume, but it sure is interesting. I wonder how much of this is due to the Protafloc tablet added during boil?
The real star of the show is my new Tilt hydrometer, which has been sending back temperature and gravity readings since it was dropped into the FV at start of primary yesterday. It seems there’s quite a bit of variation in wort temperature even when the ambient room temperature stays stable. My first thought was ‘must get a fermentation fridge set up’ in order to stabilise things, but to be honest I doubt very much what difference that would make on such a large thermal mass which changes temperature from the inside-out. Keep the probe outside and it wouldn’t pick up on the subtle changes happening in the FV, move it inside the vessel and the either the pump or the heater would be running constantly, trying to impart a change likely too big by the time it gets there. Need to park that thought for now before it gets complicated.
On a positive note, the Tilt clearly shows that fermentation is in progress, in fact I’m already 15% towards my goal! I plan to leave it another 24 hours and then start adding some pressure to the Fermzilla, hoping to tame any subsequent Krausen, insure against temperature rises, and begin the process of carbonation. If that brings the total fermentation time down as expected I’ll also have to bring forward the 6 day hop additions, but we can cross that bridge later. For now I’m really glad to have Tilt’s trend graphs as a point of reference.
