Heavy airlock again after 5 weeks in Primary

[CamG]

Hi,
I have a Double Oatmeal Stout fermenting. It went through a normal fermenting process and after about a week the airlock stopped bubbling.
At this point, my plan was to just let it sit in the primary until my current keg of Stout kicked. Didn't want two stouts on at the same time.

So today I heard heavy airlock bubbling, not typical off-gassing, but large gurgles about 1 per second. It has been in the primary for 5 weeks sitting quietly for 4 of them. Is this unusual ?

I did a google search but most of the posts related to people dry hopping or large temperature changes, neither of those occurred here.

Thanks for any advice.

Cam

 

[McKnuckle]

I can only add that this happened to me as well. For almost the same reason, too. I had a keg of stout and brewed a replacement batch with Safale S-04 yeast. It was still, sitting in a secondary carboy in my cold garage waiting for the keg to kick. It had been there for at least a month.

We had a warm spell, and the thing started fermenting again. I learned this because the solid bung popped out, which I discovered by chance. I replaced it with an airlock. Clearly, it simply wasn't done! Nothing more, nothing less. Despite the temporarily exposed opening, the beer is fine and has now been in the keg for a while.

I realize you didn't have a temp swing. Just smell and/or taste the beer. It will tell you if it's now fermenting with proper yeast or with something funky.

 

[JonM]

A change in barometric pressure will do that.

 

[CamG]

Hi guys,
Thanks for the info.
it seems to have almost stopped now. I can still see pressure in the airlock but not enough to force a bubble. I am not sure how long it was active for but no more than a day.

I used Safbrew S-33 yeast
The barometric pressure over the last 3 days has varied from 100.2 kPa to 99.7 kPa.
The temperature didn't change much, I would say no more than 2 degrees averaging around 68


I think you are right McKnuckle the only way to tell is to taste it when it goes into the keg. I sure feel better after reading you had a similar experience and it turned out ok

I will let you know how it goes.

Thanks again,
Cam

 

[ByramMike]

Just curious... what was the gravity reading when primary seemed to end? Did it change when the second fermentation ended?

 

[CamG]

Hi BramMike,
The final gravity was 1.02 I don't take any readings until I keg and I don't use a secondary, so I don't know what the SG was before it started to become active again.

For the record it was really good