Fermentation stopped then started again?

[dtgardner94]

I'm brewing my first batch of beer, it's a wheat beer, filled 2 separate 1 gallon carboys. Fermented like crazy for first couple days, settled out after about a week, then after about 12 days, fermentation started back up again with a new foam top and lots of bubbles. I've read it might be from temperature change which could totally be the reason, but if that is the reason, how much could that affect the beer? And also, what other things could it be? Thanks!

 

[BigJack]

It could well be the yeast waking up with warmer temperatures.

It could also be some other microbe having a go at your beer.

Keep an eye on it and report back. Pics could help.

 

[boydster]

What kind of yeast? I've had that happen with S-33 before. Really, any yeast that you are running on the cold side could stall and restart like that if you don't warm it up when fermentation slows down but later on move the beer to a warmer environment, but English Ale yeasts seem to be the most susceptible to that kind of thing.

 

[dtgardner94]

Its S-33. The nights have gotten down to about mid 50's and days maybe mid 70's. How much does inconsistent temp change flavor?

 

[boydster]

S-33 has a pretty neutral profile on the lower end of its temperature range. If you get up to the higher end, it gets a little fruity. Now that you have the zombie krausen, try and hold the temps consistent and if possible, run on the warmer end of the spectrum to help it finish.