Huge headspace and pale ale fermentation time

Question

I just brewed my 3rd biab batch last Saturday and pitched 3 white lab liquid yeast(i was told to do that because the yeast were expired). I was left with 15l and filtered it using a cheese cloth as I pour it in mu fermentation bucket. My fermenter is the typical 30l plastic bucket.

So I was left with 15l of headspace and controlled the temp between 20-22C. But I haven't seen any bubbling from the airlock but it smells like beer.

Should I worry, that my fermentation is not working? How long should I ferment it, if I am filling bottles next?

Thanks

Answer 1

You may or may not see bubbling in the airlock. With a lot of head space, it may be reduced, and you may not notice it at all. Watching the airlock is like reading tea leaves... could be true, could not be.

The only way to know how fermentation is progressing is to take gravity readings. If the gravity is reasonably close to the expected final gravity and does not change in 24 hours, fermentation is probably done.

You only need to worry about your yeast if after a few days gravity is still close to the original gravity. In that case you may need to get new yeast, but taste your wort first to make sure nothing else has taken over when there was no yeast active to consume the sugars; even if you have the bucket closed you risk an infection if the wort sits without yeast for weeks.

(Not an issue here, just for completeness: fermentation may also have temporarily stopped if you ferment too cold. In that case it will pick up again when temperature rises.)