Stalled fermentation?

[Quimbola]

Brewed the Austin Homebrew Milk Chocolate Stout about two weeks ago (1/29), I did a double pitch with the yeast (WLP013). My OG was spot on.

It fermented well at 64 degrees, stopped after about 5 days.

I just checked it this morning and it was bubbling again, 9 days later?

Just wondering if that is normal? The temp did drop slightly in the basement, 60 degrees.

I'm not stressed about it just curious.

Thank you.

 

[homebrewdad]

Bubbles mean nothing. Changes in temp can indeed cause them (CO2 gets released from solution). Bubbling in the airlock (or lack thereof) airlock means nothing, as your seal may not be airtight.

The ONLY way to know for sure that fermentation is done is by taking gravity readings and getting the same reading 2-3 days apart (3 is safer).

Odds are that fermentation is indeed complete - just check your gravity.

 

[Revvy]

All we know is that you have airlock bubbling, which means nothing, because it could mean ANYTHING. What's the current gravity?

The rate or lack of or whether or not it bubbles at all, or if it starts and stops has more relation to the environment the fermenter is in, rather than fermentation itself. All it is is a vent, a valve to let our excess gas, especially co2, nothing else. It's not a fermentation gauge whatsoever.

It could just as easily be bubbling due to changes in barometric pressure, temperature, or whether or not the cat or vacuum cleaner bumped into it, as it could be to because it's still fermenting.

All an airlock tells is whether it's bubbling or not... hydromter can tell you why.

 

[Quimbola]

Thanks guys, that satisfies my curiousity.

I'll still give it another two weeks until I check FG.

 

[BierMuncher]

Ideal ambient temp for that strain is 66-71 degrees. You started out a little lower and are now 6+ degrees below "Ideal" temps.

Your beer is still fermenting, just slower than might be considered normal because of the cooler ambient temperature.

No harm, just don't rush it.

 

[TopherM]

I cleaned my fermenter with oxyclean after bottling a batch yesterday, then rinsed and drained it and left the empty fermenter on the kitchen counter with the airlock on it.

This morning, my fermenter that was filled with about 99.9% o2 and 0.1% h2o had active bubbling of StarSan in the airlock.

I didn't take a gravity reading, but I'm pretty sure active fermentation was not taking place.

I've even had a 5.5% ABV beer completely ferment out without the airlock bubbling once.

Point being, the airlock is a sign of active fermentation, but it is not EVIDENCE of active fermentation.