All going well. I thought the cap had fallen and the distillation had finished so I scooped some out to test the SG and it was still bubbling vigorously in the cup. It's clearly still going but just not quite as energetically.
Smells a tiny bit like vinegar (hard to judge) which is a bit concerning, may have been some contamination early on... but don't see myself as having much choice except to let it keep going for now. Have put out numerous traps for the fucking vinegar flies and have caught dozens of them.
I found this
calculator online which claims to reveal ABV by comparing Brix measured with a refractometer with SG measured with a hydrometer. I didn't get the SG or the Brix at the start because my bits and pieces hadn't arrived by post yet so putting the figures into this little formula is the best I can do. Anyway current Brix is 5 and current SG is 1.010 which gives a hypothetical ABV of 2.64% after a week of fermentation. Will test again in a few days to see if these instruments are actually yielding any useful information.
I suspect this stuff is too full of suspended solids to yield a useful SG reading but it was fun to muck around with it. The Brix reading was very indistinct once again due to all the suspended solids.