Oh, thanks very much! Lots of useful information here. It doesn't taste bad or hot to me, but I've never tried unfinished mead until I started this so I've nothing to compare it to. I have been trying to keep it consistently at about 18-19 deg C. Apparently the range is 15-20 deg C for D47. It's been quite challenging but the lowest it ever drops is 15 deg C and the highest is 19 deg C, so it's an improvement from the setup I had before it got cold here. I have also been stirring it gently to resuspend the yeast every couple of days. Curiously, it goes through periods of bubbling once every few minutes for a while and then periods of not bubbling at all. I'm not entirely sure what to make of that, though I assume temperature changes are contributing somewhat.
The bread yeast thing sounds interesting. Is that supposed to add more nutrients to try get the yeast going again? If so, why not just add more nutrient?
I'm surprised that my mead is about 10% according to your calculations. I hadn't really given it much though, but I was expecting it to finish around 13% like a typical red wine. If it still has a lot of fermenting to go, I guess it will be quite strong if I can get it finished! Nevertheless I'm alright with that. It's too sweet right now to be considered "good enough". I'm not done with it yet.
Does potassium carbonate change the flavour of the mead at all? If not, I'm happy to get my hands on some and add it right away, but otherwise I'm not so sure. I might see if I can go without it for a bit. I was originally not planning on using chemicals at all.