Originally Posted by Twinstacks
Ok thanks guys. The wine in my demijohn now seems to be getting a head on it like beer ha ha is this normal. I have a heat belt around it and it's near the top keeping the wine at 24 degrees since the start.
You can stop seeing bubbles for a couple of reasons.
1. Gas escaping by another means (i.e. poor seal)
2. Yeast have stopped working
Yeast can stop working for a couple of reasons.
1. No more food (i.e. sugar) for them to munch on
2. Alcohol level is too high (i.e. too toxic of an environment for the yeast to keep working)
3. Other causes of "stuck" fermentation. (I don't know all of these. Temp is one, but other things can also cause yeast to quite premature as well)
So yeah, getting an SG is the way to know if it's "done" or if the yeast just quit working early for some reason. And check the seal to make sure gas isn't escaping another way!
(Disclaimer - I'm still new at this myself, so take everything I say with a grain of salt!)