10:30 am Airlock on batch #2 is popping at about every 3 to 4 seconds! Love that! Batch #1 is showing slow change toward clearing.
12:25 pm Uh-oh! Just did a check on my batch #2 and the airlock has cider in it!
I quickly sanitized another airlock and carefully/quickly switched it out. It could not have happened more than an hour ago. When I last looked at about 11:00 am, it was clean and bubbling about every 3 seconds. I went to a brew forum to see if there was anything on the subject, and there was. Since I have been so careful about sanitizing everything, it sounds like it will be ok. One person said that if some water from the airlock got into the fermenter and a bad bug just happened to get in with it, that the yeast had been going long enough and it would probably not survive.
As far as the cause, it could be that the bucket is pretty full and the temperature in the house is around 76 degrees. With the yeast taking off, it just hit the top of the bucket. (I decided to run the air conditioner for a couple of hours and get bacj to 72 degrees.) I have seen it suggested that the airlock should be filled with vodka or a diluted sanitizer solution. I think I would rather go with vodka. I replaced the airlock with a sanitized one filled with plain water, but maybe I’ll dribble a little vodka into it.
Update 9:30 pm I did add a small amount of vodka to the batch #2 airlock shortly after the last entry. Seems to be back on track, bubbles still every few seconds. Batch #1, gauging progress by the most important componant, the 1 gallon carboy, continues to improve, slowly, but steadily.