Our first batch of hard cider has been bubbling merrily away in the closet since Oct 27. Monday, Nov 3, (one week later) I pulled the jug out to have a look at it.
The scummy froth on top has dispersed, and the movements of the air lock had slowed considerably. It is now bobbing about 3-4 times per minute.
The bottom of the jug is full of this sediment, which, so I read, is the dead bodies of spent yeast, otherwise known as “the lees.”
Since everything seemed to be going quite nicely, and the fluid levels seemed in no danger of rising, I sterilized the funnel again, and removed the air lock long enough to top up the jug. I also took the opportunity to draw some out with a sterilized 10cc medicine syringe and taste it. It was light, sweet, and fizzy, and did not taste very strong.
Then I replaced the air lock.
After watching for a few minutes it began bubbling briskly, but not aggressively. There is a constant stream of tiny bubbles gently floating to the surface from all over the dark interior.
Now we wait until this process stops, before drawing it off into secondary fermentation.
Little Farm in the Big City 