Airlock Bubbling - stops and starts again...

[mudkumpf]

Hi,

I'm brewing my first ever batch, so not quite sure what to expect regarding Airlock bubbling.

Initially it bubbled away nicely for 3 days or so, then stopped. A few days later I took the lid off to add the hops. It then started bubbling again for about a week and then stopped.

I left for about 10 days, and then decided I'd best take some hydrometer readings to see if it's stable and ready to bottle.

On replacing the lid after taking the first reading, it's started bubbling again.

Is that normal behaviour? I'm guessing it means that it's still fermenting (perhaps slowly as the temp has been at 18-20, rather than 20-25) but it's the sudden uptick when taking the lid off (or adding the hops / hydrometer?) that's confusing me. I'd have expected it to calm down and stay calm?

Cheers,

Kieran

 

[RM-MN]

When the yeast are real active like they will be for the first 2-3 days they produce CO2 as a byproduct of fermentation, lots of it. CO2 can be dissolved in the beer (that's what causes head formation), more than the beer can comfortably hold. Whenever you disturb the beer it will release some of the stored CO2.

CO2 is only produced for a short time. Here's an article that every new brewer should read.

http://www.brewgeeks.com/the-life-cycle-of-yeast.html