Air sucked into carboy

[Greg Anderson]

I am making hard cider. I started the cider in an open bucket. Once it got going I transfered it over to a carboy and put an airlock on it. (This kind of airlock: http://www.leeners.com/pictures/UnivStoppers.jpg) The cider is sucking air--and the water in the airlock--back into the carboy instead of pushing air out. I have had this happen before and it eventually stopped doing this and it ended up turning out fine. Does any body know why this is happening or if it is important?

Thanks Greg

[conor]

I have the same type of airlock and have the same thing happen, at least I think. What happened in my case was that I filled up the jug too high, maybe an inch from the rubber stopper, and the bubbling caused my mead to bubble up into the airlock. It has now stopped as the bubbling became less vigorous, but for awhile some of the water was being pushed back into the jug because the airlock was almost overflowing.
In any case, as long as you have bubbling, the pressure should be going the other way (out of the carboy and airlock). If this eventually happens, the small amount of air and water that was sucked in will probably not be a problem. If this does not happen, then the problem is not the airlock, but most likely a lack of yeast growth. Was the cider bubbling before you put the airlock on?

[Greg Anderson]

It was bubbling but rather weakly. This might be it. Maybe I should just leave it longer before putting it into the carboy?

Greg

[Tim Hall]

I've had this happen before...happened after moving the ferment from a 55-degree incubator to room temperature after the fermentation ceased. The temperature difference caused enough negative pressure to gulp air and airlock fluid inside the ferment. If your must was significantly cooler than the ambient temperature before the yeast got well underway, this could be the cause.

I always make it a point now to make temperature adjustments slowly and pitch yeast at or close to primary fermentation temperature. Slow temperature adjustments are also easier on the yeast.

[Greg Anderson]

That is definitely something to keep in mind but I am afraid it is not what has happened here. I have done everything in the same room which has stayed stable at about 24 degrees celsius (75 fahrenheit). I took it out of the carboy a couple days ago and stuck it into a bucket and let it get going again. I stuck it back in the carboy just now. Hopefully it will work out.

Thanks.