Originally Posted by Izzoard
Also, the alcohol meter: does it work by floating somewhat and the depth gives you the reading? This would imply I need to decant out of the demijohn - not very practical!
Yes it does work by floating. You will need something called a wine thief to take out samples to test. I take my samples out and put them in a graduated cylander to test, then dump it back in. Well I put back in what I don't taste test
I'm not sure how much good this will do you because you need to take a reading before you pitch the yeast to compare with later readings. This will tell you the ABV. The meter will be useful in helping you decide when the fermentation is done. Be sure to sanitize everything you use to take measurements (hydrometer, wine thief, graduated cylanders and your demijohn stopper if it touches anything)
Good luck with the cider!