I racked my graff cider into primary a week and a half ago. Fermentation slowed down after 4 days -- I was lucky to see the yeast burp once every 5 minutes or so.
This weekend I took a gravity reading (1.010) and tasted it (good, but a bit too tart). The following day a layer of krausen began to build up, and now I've got a 1/4 inch layer of krausen on my cider. My question: where did this krausen come from? Judging by the gravity reading and having seen no airlock activity at all, it seems to me like primary fermentation is over!
This cider is my third brew ever, so I'm a total newbie. Any of your thoughts would be greeeatly appreciated.