Can beer just start fermenting again?

[Keither]

Hi, I'm relatively new but I've got a couple of dozen successful batches under my belt. In fact all my attempts so far have yielded tasty beer. One kind of beer I really like is the "Brooklyn Brew shop" "Everyday IPA". I pretty much brew another batch of that as soon as I've drank up all of the previous one. I love it.

Anyway, I always do the same thing every time, it's all-grain, and I brew 2 gallons at a time and use the yeast that comes with the grain. I don't check gravity, I just hope for the best. It always turns out fine.

This particular beer always ferments rather vigourously and starts within 8 hours or less of brewing. This time was no exception, it fermented energetically for a day, and then settled down just as quickly. Usually at this point I wait two weeks for it to settle out and clear, then bottle. Not this time. This time, it fermented just like always, and then, ten days later, the airlock started to release gas and a layer of krausen is forming AGAIN! After ten days of behaving just like normal, as in, no activity! It's clearly fermenting again, with a healthy-looking layer of foam about a centimeter thick on top and gas bubbling out of the airlock.

What the heck is going on in there? Normally this beer would be clearing by now, ready to be bottled in another five days or so!

 

[CBMbrewer]

Can you post a pic? How does it smell?

 

[wyoast]

Can you post a pic? How does it smell?

+1 on that..sounds suspicious,, did you happen to warm it up?

 

[Pratzie]

Post a pic. It may be infected.

 

[Keither]

OK I will try to post a picture tomorrow. The gas coming out of the airlock just smells like hops and yeast, you know, normal "beer" smell. The weather is warm but not really over room temperature. It's hard to imagine how it could have gotten infected.. but maybe it is. It is cloudy, but it hadn't really started to clear anyway. Frankly it looks normal other than it is fermenting again. Weird.

 

[Keither]

I've done a search on "beer started fermenting again" here and I think I've decided that the temperature must have increased and CO2 came out of solution or something. It does seem a bit warmer around here. I removed the airlock and took a quick sniff, it just smells like beer in there and there's nothing weird floating on top other than a layer of foam. The beer fermented just like it always does the "first" time. I think I'll just wait until it clears and then bottle it. Even if it's infected there's nothing I can do about that at this point. Might as well try to drink it. It doesn't smell funny.

 

[KeyWestBrewing]

The airlock bubbling again isn't that weird. Change in pressure can cause that. The second krausen though is weird. Post a pic.

 

[Pratzie]

Yeah I wouldn't dump it. Ur already this far along u might as well commit, u don't have anything to lose at this point. Just wait til it dies down, take some gravity readings and bottle.