Does fermentation chamber slow fermentation rates and/or affect ABV?

[whovous]

I am very new to all of this, but my recipes have all included overpitching US-05. I usually brew 2.5 to 3.0 gallons and pitch an entire packet after oxygenating. Fermentation was always in a dark closet. It started fast, and after about 72 hours the bubbling pretty much stopped.

This time is different. I put the wort into a fermentation chamber (old fridge with Fermostat) at 62F on a Monday afternoon. It is 144 hours later, and I upped the temp to 64 early today. It is still bubbling quite vigorously and audibly; not as much as it was after 24 hours, but still at least a bubble per second, and still some standing bubbles in the StarSan side of the blowoff tube.

Is this because my temps are better controlled and probably 6-10 degrees lower on average than they were in the closet? Or I am likely to wind up with a lower final gravity (and higher ABV) as a result of all this extra bubbling?

 

[GilSwillBasementBrews]

It's doing what it's supposed to be doing. You're fine. The cooler temps are keeping the fermentation from running wild. You will experience slightly longer fermentation than at room temp with no control. But that's a good thing. By keeping the fermentation temps in check you reduce ester formation and will have a better resulting product when it is complete.

 

[GilSwillBasementBrews]

And it shouldn't effect your FG the yeast are going to eat what they eat. You're only controlling how fast they eat it. Lower temps = slower

 

[NervousDad]

An over pitched ale at 62 will give you a very clean beer, almost bordering on a lager. As far as attenuation, after ~72 hours you should have began to ramp up your temp to ~68-70f. That will help ensure that the yeast will finish the job.

The biggest problem with uncontrolled fermentation is that the fermentation will generate a lot of heat then the heat drops when the fermentation slows. This causes the yeast to drop of and flocculate leaving you with an under attenuated beer.

 

[whovous]

Thanks GilSwillBasementBrews. I suspected that was the case even though it was bubbling pretty doggone vigorously for the first three days. I was away for three days, so I've not tracked every last bubble, but it is my completely subjective suspicion that it done more bubbling in six days than the prior batches did in three.

I made some definite mistakes with the prior batches, and they still came out fairly decent, so I am really looking forward to this one as I feel like I am starting to get the process dialed in. I intend to keep making the same beer until I think it is great.

 

[whovous]

Sorry, double post.

 

[whovous]

I'd planned to ramp the temps up sooner, but it seemed so vigorous, I let it go. I will ramp sooner next time. This time I am adding 2F every 24Hrs.