Does cider in oak barrel need airlock during secondary fermentation, for the gas to escape?

Question

I have 200 litres of cider which was racked yesterday into 2 x 100 litre oak barrels. Before racking, the cider was still fermenting at a rate of about one bubble (through the airlock) per two minutes. This was due to cool weather here since October and the recent addition of a heater to the brewing room about a week ago.

Both barrels have been stoppered with a cork bung with no airlock.

Can anyone tell me if this is safe? Will the CO2 be able to escape through the barrel without an airlock at this rate? Likely to be pretty vigorous at first due to the air mixed in while racking.

Also any thoughts on the taste - will the oak taste be way too strong if I leave it maturing until say, April?

Answer 1

You absolutely should have an airlock on your barrel. This allows fermentation to continue (fermentation halts under enough pressure).

You will want to check the taste every month at minimum to see if it's too oaky. New barrels (barrels not previously used for whiskey or wine or anything) will impart much more oak flavor into your brew, so make sure you check the flavor often. You can easily sanitize a wine-thief or turkey baster and pull samples from the barrel to do this.

When your aging is concluded, transfer to keg or bottle to carbonate.