Weird...renewed airlock activity

[Just-a-Guy]

I brewed up a True Brew IPA kit (LME and grains) on 2/11. Airlock had activity for four days or so then slowed to nothing visible. It's been sitting quiet ever since (as far as I know anyway, I don't watch it 24/7...although I'd like to).

Walked in there just now, and all of a sudden it's bubbling, about 2 a minute or so. What the heck? What would cause a quiet fermenter to suddenly become active again? Is this common?

TIA,

Mark

 

[brewmax25]

Has the temperature of the room where the beer is fermenting been rising?

 

[Just-a-Guy]

Now that you mention it, I think it has probably gone up a little. We have had a "warm spell" here in NY (it's been a warm winter anyway). Temps in the basement room where all my beer stuff is tend to be around 62-66, mostly 64-66. Right now it's 64 in there, but it has been warmer the last few days. Hadn't thought of that. Safe to assume it won't have any bad effects?

 

[NineMilBill]

No - no measureable negative effects.

 

[Just-a-Guy]

Thanks.

 

[AdamPag]

if the air pressure changes then yes it can bubble even though its not fermenting. The past few days in NY we've had a low pressure system (rain) and if your Head space in the fermentor is at a higher pressure then it will automatically seek to move it self to a lower pressure. Check out a wiki on fluid/aero dynamics.

 

[Just-a-Guy]

if the air pressure changes then yes it can bubble even though its not fermenting. The past few days in NY we've had a low pressure system (rain) and if your Head space in the fermentor is at a higher pressure then it will automatically seek to move it self to a lower pressure. Check out a wiki on fluid/aero dynamics.

Interesting. Makes total sense. If that's the case, I'm probably not getting any additional fermentation, just air pressure adjustment, right. I was planning to rack it to a secondary this weekend for clearing, and bottle next week some time. Was concerned that maybe it hasn't finished fermenting. Just went out there and drew a sample to check the SG, and it's just under 1.020. It was about that a week ago, too. Hm. Seems high to me (OG was 1.054). Oh, well, it tasted pretty good....

 

[RuffRider]

I brewed a batch of that True Brew IPA. It came out pretty good. If I were to do it again, however, I would dry hop it. As I recall, the kit doesn't come with enough hops to dry hop with nor do the directions mention it.

As far as barometric pressure changes, hmmmm, not so sure. I agree that changes in atmospheric pressure could affect the differential pressure between your fermentation vessel and the atmosphere. But, I'm not convinced those changes would happen fast enough to cause the airlock to bubble twice per minute. I would be more inclined to think that the rise in temperature restarted some fermentation activity. Is it still going? Is your gravity changing again? When I brewed that kit, my FG was 1.011.

Just food for thought.

 

[BrewKnurd]

Either temp increase or pressure decrease could easily cause this. Both of those decrease the solubility of CO2 in your beer, so the beer starts offgassing and that CO2 bubbles your airlock.

 

[WooHokie]

you don't have to move it to a secondary fermenter. instead, ferment a different beer in that second fermenter!

 

[Just-a-Guy]

I brewed a batch of that True Brew IPA. It came out pretty good. If I were to do it again, however, I would dry hop it. As I recall, the kit doesn't come with enough hops to dry hop with nor do the directions mention it.

As far as barometric pressure changes, hmmmm, not so sure. I agree that changes in atmospheric pressure could affect the differential pressure between your fermentation vessel and the atmosphere. But, I'm not convinced those changes would happen fast enough to cause the airlock to bubble twice per minute. I would be more inclined to think that the rise in temperature restarted some fermentation activity. Is it still going? Is your gravity changing again? When I brewed that kit, my FG was 1.011.

Just food for thought.

Thank you, that experience is very helpful to me. I went out there just now and stood for a couple of minutes, and I didn't see any activity (although there are foam bubbles in the airlock, which has a Star San solution in it). It's 68.4 degrees out there right now, warm here. I think I'll wait a couple of days and check the SG again.

By the way, what kind of hops would you recommend to dry hop this brew? I have some Cascade whole leaf hops in the fridge, and my local home brew shop is close by.

Thanks!

Mark

 

[AdamPag]

at 3 weeks you're pretty much done man, I have brews start around .06 and finish around .018 so you arent too far off. If you're going to dry hop im pretty sure most people still arent bothering with secondary and just dry hopping in primary

 

[Just-a-Guy]

at 3 weeks you're pretty much done man, I have brews start around .06 and finish around .018 so you arent too far off. If you're going to dry hop im pretty sure most people still arent bothering with secondary and just dry hopping in primary

Right, thanks. I guess that's the next decision. I do need the bucket and have an empty 5 gal carboy. And last time I did a secondary I was able to watch the beer clear over a week or so (after 3 in the primary). So my inclination is to rack it to the carboy, add some hops, leave it for a week and then bottle. That way I can put another batch in the primary. And yeah, I could buy another bucket, but I already have three and SWMBO is getting a little...uh, well, I'm starting to "those looks".