last minute fermentation re-start

I am a beginner. I have only brewed 7 times. I am brewing a Sierra Nevada Pale Ale extract clone. My OG was supposed to be 1.051 but it ended up being 1.044. My final gravity is supposed to be around 1.013. I am using White Labs WLP007. I made a starter using a stir plate. The brew fermented strong for 5 days and it mellowed out until fermentation "completed" by day 7, or so I thought. I am at day 15 and had just finished cleaning up all my bottles when I heard the familiar bubbling up sound. I could not believe my ears. Fermentation started up again! It is bubbling 15 seconds apart. I took a gravity reading and it is giving me 1.006. I have not opened it since it started fermenting. I really don't understand what is going on here. The beer tasted really nice too. I put my bottles away and will wait it out but what can be the reason for this? any experiences with a similar situation?

Thanks.

Give it another couple days and take another reading. It has probably stopped and what you are getting is off-gassing. It's basically just going flat.

Very well could be co2 gassing off.

Have you taken any readings since the one mentioned?

Rick

I took the first reading of 1.006 today at 2:30pm, it is now 10:00pm and still bubbling about once every 15 seconds. I will take another reading in the afternoon tomorrow. I want to avoid bottle bombs at all cost. If it is co2 gassing off then it should be ok. Only the hydrometer will know for sure. Is tomorrow too soon?

Because it has been in the fermented do so long, if it is dropping, it is dropping slowly. You'll want at least two days between readings.

See this for more information:
http://woodlandbrew.blogspot.com/2012/11/when-has-my-beer-finished-fermenting.html

Has the temperature changed, a weather front gone through, the fermenter been moved or bumped? Any of those things can make the airlock bubble without any fermentation taking place. Only your hydrometer reading can be relied on for a determination of fermentation being done.

No temp changes and no movement before I got to wondering and moved the fermenter to take a gravity reading. I was counting my Mississippi's too slow yesterday. It's more like 25 seconds apart. But it has been constant now for 18 hours. I guess I will know tomorrow after a second reading if its co2 degassing or real fermentation. I really was hoping to bottle this weekend but you can't hurry a living process I guess.

ding_brew said:

moved the fermenter to take a gravity reading.

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In that case I'm 99% sure that's all that caused the bubbles. unless your fermentation temperature was less than 60 and the gravity was over 1.080 I bet it's done.

I moved it after it had been bubbling for a few hours so I could check on the gravity to see what was going on.

I'm hoping its done too but I don't want to risk any bombs. I am surprised no one has run into this before.

Krausen could have fallen through and disrupted the surface tension holding the CO2 down. Likely just off-gassing.

People have run into it before. Off-gasing due to minor temperature or pressure changes or looking cross eyed at the beer is not uncommon.

Give it another gravity reading after a while and you will know what's up. Hopefully it is stable. If it has dropped like a stone, you may have more to worry about.

3 days later and gravity is at 1.004. It doesn't taste like vinegar so I'm going to risk it and bottle. It's still bubbling every 34 seconds or so but I guess I will risk it. Any recommendations on if I should go with the standard 5oz or should I do less?

So, you're saying it has dropped a couple of points over the last few days? I'd give it another reading in a couple of days. If it stabilizes, you're probably fine, but if's it's still giong down, I'd be a bit concerned that there is more than just your normal yeast activity going on there.

ding_brew said:

I'm hoping its done too but I don't want to risk any bombs. I am surprised no one has run into this before.

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I ran into this on my last two batches. OG's of 1.060 and 1.070. They stopped bubbling after 5 days and I measured them both at 1.010 on day 7. I swirled the buckets and they both bubbled slowly for the next 4 days. Moved them to secondary on day 15. Am in no hurry to bottle them...two more weeks and then I'll bottle.

Ok will wait 2 more days. I have never had a beer go below 1.008 before but although it tastes pretty dry, it doesn't taste bad at all. It feels like its going to need a few extra weeks in the bottle. Maybe I over pitched when I did my starter? I did let it go for 2 days in the stir plate.

ding_brew said:

Ok will wait 2 more days. I have never had a beer go below 1.008 before but although it tastes pretty dry, it doesn't taste bad at all. It feels like its going to need a few extra weeks in the bottle. Maybe I over pitched when I did my starter? I did let it go for 2 days in the stir plate.

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I brewed a cream ale recipe from Listermann's last month. OG at 1.045, finished at 1.000, very dry in the hydrometer flask. In the bottle at two weeks - not dry like the hydrometer, turned out excellent.

After 3 weeks it never stopped fully bubbling. It was more spread out. About every minute. I managed to get a consistent gravity of 1.004 after 2 days of waiting so I bottled with DME and will leave it alone for at least 3 weeks. Thanks every one for your input. I have never experienced a start-stop-start of fermentation.