Chest Freezer and Thermostat

[STL_Lucas]

So I got a GE 7.0cu.ft. chest freezer and a Johnson Controls A419 Thermostat so I could keep better fermentation temps and hopefully try out some lagers soon. For the time being I'm just testing out the temps and trying to get it calibrated at about 64* and while it holds temps very well only losing a degree every couple of hours or so when it finally kicks back on the temp drops all the way down to the low 50s and then slowly back up to 64 until it kicks on again. Do I have some of the settings wrong or what can I do to keep it more stable in the low 60s?

Settings are currently at:

SP: 64
dif: 1
Asd: 1
OFS: 0
SF: 1

 

[bob352]

Is the freezer empty?
If so, try with a fermenter filled with water and tape the probe
to the side of the fermenter.

 

[STL_Lucas]

I will try that and see, thanks

 

[Cyclman]

I have that exact setup. Put the probe into a plastic bottle filled with water, cap it off. Turn it on an hour or two before you will be fermenting beer in it, you'll be fine.

I ferment at the bottom of a yeast's temp range, beers have come out awesome since I got it.

 

[STL_Lucas]

Thanks Cyclman! I'm pretty excited about it. My first few batches all fermented too warm and had a big banana flavor so I've had to bottle condition them for months in order to drink them, then my last batch fermented too cold and the yeast dropped out before it was done. I'm really hoping with this new setup I can dial in the fermentation temps and make some good beer!

If I do the water in the bottle trick, will it keep the fermenter cool enough even during active fermentation? I was thinking about sticking the probe to the side of the fermenter during the primary fermentation stage to make sure the temp didn't spike inside the fermenter. Whats your experience with this?

 

[Newsman]

Thanks Cyclman! I'm pretty excited about it. My first few batches all fermented too warm and had a big banana flavor so I've had to bottle condition them for months in order to drink them, then my last batch fermented too cold and the yeast dropped out before it was done. I'm really hoping with this new setup I can dial in the fermentation temps and make some good beer!

If I do the water in the bottle trick, will it keep the fermenter cool enough even during active fermentation? I was thinking about sticking the probe to the side of the fermenter during the primary fermentation stage to make sure the temp didn't spike inside the fermenter. Whats your experience with this?

I think either way should work. I normally do the probe in the bottle, but the last ferment I did, I taped some bubble wrap to the side and put the probe between the bottle and the bubble wrap so that the probe is ONLY measuring the temp of the ferementer and not the ambient temp in the freezer. I have some beer I made yesterday that is fermenting (hopefully --- didn't see any activity several hours after I pitched yesterday...) right now so I probably ought to move the probe from the bottle to the side of the carboy.

 

[STL_Lucas]

Good idea with the bubble wrap. I think I'm going to try that out. Seems like after a day or so of being on and hooked up and temp is staying a lot more consistent. Going to try a brew this weekend to start breaking this thing in.

 

[Newsman]

Good idea with the bubble wrap. I think I'm going to try that out. Seems like after a day or so of being on and hooked up and temp is staying a lot more consistent. Going to try a brew this weekend to start breaking this thing in.

Well, I can't take credit for coming up with the idea... it was something I found on one of the forums here...

 

[BigFloyd]

+1 on taping the sensor to the fermenter and insulating over it. That has worked very well for me.

Another useful technique is to chill your wort to a few degrees below the initial target ferment temp before pitching. That will not only help with flavor, but will also allow temps to equalize faster between the bucket/carboy and the freezer.

Since you now have the wonderful ability to control ferment temps, after you run it at 64*F for 4-6 days and the activity slows, slowly increase the temp about a degree a day until you get to 68-70*F. Leave it there to finish up. That will assist the yeast in the cleanup of their by-products.

 

[STL_Lucas]

Thanks BigFloyd! Can't wait to try this out!