Ok, hands up, who's perfect ?..........
After I mixed the batch up, I rehydrated a sachet of D21 (with hindsight, I should have used K1V-1116). Now as is my habit (being a little lazy), I sort of follow the instructions, but not always with total accuracy.
I didn't test the water temperature when rehydrating the yeast, I just made it hand hot and added about 100mls of the must and about 8 grammes of GoFerm. Once it had been sitting for about a half hour, there wasn't much, if any, foam or bubbling yeast on the top of the rehydration liquid, but I figured I'd left it too long for that - I now believe not (note too self, read up on making starters).
The yeast got pitched. The next day, there was no activity that I could see when I opened the bucket to see if I could work out what was going on. I just sanitised the electric balloon whisk and aerated the must. Having had a wank day at work the following day, I forgot to aerate the must. The day after that, I did my check i.e. I was only waiting to see some sign of fermentation commencing so I could add the FermaidK/DAP (1tsp/half tsp) mix..... nothing, so again, I figured just blitz the must again with the whisk as above.
On the fourth day, I did my check and still nada. "Bugger" thinks me, it looks like I've got a duff batch of yeast, either that or the high starting gravity has affected the yeast (I think it's called osmotic shock, I don't recall the exact phrase), so I'll have to probably pitch again at the weekend if it's not going tomorrow, but as an ill-thought out idea, given the high SG, I added a further teaspoon of GoFerm when I was whisking.
Tomorrow came (yesterday), and work fucked me over, I ran out of hours to get back and got stuck out, in a layby just of "the 25". So no check, nothing.
This morning, I got to have a look to see if anything has happened only to find, that not only has the bugger started fermenting, but that it's also dropped about 25 points i.e. on checking, the must gave me a gravity of 1.115! Ah well, I decided, not to worry. The delay in the batch starting was just a prolonged "lag phase". Though whether it was the wrong temperature at rehydration, or the high SG, or whatever, it's now underway.
I've just given it a good whisking, and added 1tsp of FermaidK and half tsp of DAP. I intend trying to remember to whisk daily, maybe to the 1/3rd or the 1/2 sugar break, I haven't decided yet. Probably the 1/2 break, because of the high gravity and that a 140 drop in gravity (presuming dry at 1.000) represents about 19% ABV - D21, from memory, is good for 16% - which is why I thought of the hindsight of using K1V-1116, it's tolerance is 18% and I saved half a jar of the tropical honey, which might turn out to have been unnecessary. We'll have to wait and see. If I can overdrive the yeast some, to achieve greater than 16%, then that'd be good. After all, I don't intend this being ready for drinking any time soon. Just to get it finished fermenting, back sweetened (after the ferment has finished as I'm gonna use more of the tropical honey if I need too), then cleared and ageing.
I suppose I didn't make sure about the temperature of the rehydration liquid, as I was being impatient! Can't say for certain, just that as with anything mead related, patience is a virtue.......