Variable Capacity Lid Leakage

[moo...@gmail.com]

Hi All,

This problem has been asked and diagnosed in several threads before, but I haven't found an exact answer to what I'm experiencing and thought I'd try to frame it specifically to what's happening to me.

I've racked my cider off of the primary / turbulent fermentation into a 110L variable capacity Speidel tank at around 1.004 sg to finish and age a bit over the winter. I was planning on placing the lid directly on the cider, but when I do, about 3-4 hours later, cider is seeping up through the airlock and spilling everywhere. This keeps happening even when I reset the lid. The pressure is staying constant on the gauge, cellar temperature hasn't changed, and the fermentation seems slow enough that it's not the problem (though that could easily have something to do with it). I'm guessing based on the other threads I read that the problem has something to do with air pockets and displacement, but I was curious if anyone could explain how they do it when they're setting the floating lid directly on the cider in a smallish tank like this.

I know I can just allow a little bit of headspace by holding the lid up off the cider and inflating, but in the variable capacity tank I did that with in an early pressing that had fermented to dry, I had film yeast develop where the tank was above the liquid—which to my mind, was the whole problem the floating lid was there to solve. It has also occurred to me that maybe I'm just not intelligent enough to use variable capacity tanks.

Matt

[gareth chapman]

If you've dropped the lid right down onto the cider and it's still fermenting then it will probably bubble through the air lock. Lift it off a bit to give the CO2 somewhere to go before going through the airlock, the headspace won't matter as it will be a blanket of CO2 anyway.

[moo...@gmail.com]

Thanks for the reply. Sounds like I just need to monitor it and when fermentation is totally stopped, then I can drop the lid down for aging. 

Just out of curiosity, with a fermentation that slow, why isn't the CO2 just blowing off through the air lock? Is some CO2 getting stuck at the edges of the lid (it's a curved lid) and forcing the cider up through the airlock in the center?

[gareth chapman]

Quite possibly.