intermittent ferment

[pattim]

I brewed an AHS kit (my 4th) of chocolate raspberry stout. The airlock bubbled along happily for 3 - 4 days then stopped.

It was their standard kit options (I think it's called extract/partial boil) but I added extra boiled cocoa to the cooling wort (stir well). I had pitched White Labs WLP009 and WLP013 and had read in those comments that 09 attenuated very rapidly, so I thought that's why it stopped bubbling so quickly. But when I jostled the fermeter bucket yesterday (5 days into ferment), CO2 literally blew out and it started bubbling (one every 2 - 3 seconds) again. That was last night. This morning, the same thing again. I guess I'll keep giving the bucket a little "swirl" once a day until that doesn't happen any more. But I'm worried about how the yeasties will do their "clean up" bit if they can't even ferment without help. I'm not planning on doing a secondary, so I'm also worried about sediment not having time to settle.

Does anyone on here have experience with what is happening and how it turns out?

 

[Revvy]

What's the gravity? You don't have "Intermittent fermentation" there's really no such thing, you have "Intermittent airlock activity" which only means...

That you have intermittent bubbling...which means absolutely nothing, except that your airlock is stopping and starting, NOT that you fermentation is.

Your airlock is NOT a fermentation gauge, despite what instructions or other people may have said. It is a VENT, and VALVE to release EXCESS co2 as needed. The amount of bubbles have no correlation to some concrete rate of fermentation. Initially there may be lots of bubbles, because lots of co2 is being generated in the first few days of fermentation. But eventually there's going to be less EXCESS co2 being produced, that doesn't mean fermentation is done, it just means that since most of the sugars have been consumed, the yeast are farting co2 less. SO the rate may change, or it may stop completely because there's no EXCESS being produced.

That's why you need to seperate the idea of bubbling = fermentation from your mindset.

Don't stress about what an airlock does or doesn't do. 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.

Fermentation is not always dynamic...just because you don't SEE anything happening doesn't mean that the yeast aren't happily chewing away at whatever fermentables are in there....the only way to know comes from gravity readings, and nothing else.

"action" is not a good indicator of anything...What do the numbers read? The only way to know what a beer is doing is with a hydro reading....

 

[pattim]

Thanks. It wasn't that low, if I recall correctly, about 1.04 - I wasn't worried about the stopping of bubbling (or the airlock activity per se) so much as the fact that it started back up after I swirled the bucket (that much extra CO2 yields bottle bombs I read here), and how much CO2 litrally blew out of the airlock (and kept blowing for 2 - 3 seconds) when I agitated the bucket. Same story a day later.

 

[lowtones84]

Agitating the bucket like that is probably just knocking Co2 out of solution, which then rises out of the airlock. Swirling the bucket isn't going to jumpstart fermentation fast enough to instantly get gas out of the airlock if you think about it. I don't think you need to jostle or disturb it anymore, as you'll probably just keep getting co2 out of the liquid.

 

[pattim]

Agitating the bucket like that is probably just knocking Co2 out of solution, which then rises out of the airlock. Swirling the bucket isn't going to jumpstart fermentation fast enough to instantly get gas out of the airlock if you think about it. I don't think you need to jostle or disturb it anymore, as you'll probably just keep getting co2 out of the liquid.

Thank you -that's what I was thinking - but the airlock bubbles were completely stopped before swirling, and afterward (after the blowoff stopped) the bubbles are back at 1 bubble per 5 seconds and stay that way for hours. Folks in the Forums seem to watch bubble timing, at least in the early stages of ferment. I thought maybe the cocoa powder had settled and taken yeasties with it somehow and then covered them with a layer of cocoa powder. Maybe this happens because I didn't boil the cocoa long enough? This is where a glass carbouy would have been nice.

 

[Revvy]

Folks in the Forums seem to watch bubble timing, at least in the early stages of ferment.

Um, no, only new brewers do, and usually one of us comes along and corrects that perposterous notion, that it actually has a correlation...

 

[pattim]

*bonk!*

 

[pattim]

*bonk!*

So no bubbles, and SG hasn't changed in days. So I'm going to try pitching some more yeast - I read here that sometimes helps.

 

[RM-MN]

So no bubbles, and SG hasn't changed in days. So I'm going to try pitching some more yeast - I read here that sometimes helps.

Helps what? What problem are you trying to solve by adding more yeast?

 

[StanJohnson]

I'm a little confused pattim. Your first post say that you had bubbles for 3-4 days. Sounds like you had fermentation, which is a good thing. Then you say "...SG hasn't changed in days". So your hydrometer reading is the same now as it was when you first started? Are you sure you are reading it correctly? I just brewed my first brew, an all grain BIAB Saturday. I never saw bubbles, but I could smell it. Probably a leaky lid seal. I don't plan on even taking a hydrometer reading until Sunday. I think you'll be fine.

 

[Ma23456]

Your fermentation is doing fine I would say leave it Alone for an other week then check the fg.. Messing with it will add more trub that needs to settle, as well as the majority of time during fermentation occurs during the phase they call the lag phase which is basically aging where the yeast converts diacetyls to ethano Rdwahahb