My fermentation Chamber thoughts

[rtracer]

So I finally found a decently priced used Standup Freezer. I fit all my needs, cheap, small standup that will fit two carboys.
I am currently fermenting my APA I brewed Monday(WLP001) and conditioning my IPA I brewed Thursday almost 2 weeks ago.

I read all the ways of monitoring/controlling beer temps, and I opted for the controller sensor hanging in the air in the center of the freezer. I am in the party that thinks that having the controller attached to, or in the beer, will cause big undershoots in temp.

Anyways I have an indoor outdoor temp sensor with the probe attached to the outside of the carboy and insulated to monitor actual beer temps.

I chilled my wort to 69, pitched yeast and threw in the chamber Monday afternoon and set controller to 67. Came in Tuesday morning and beer showed 67.. At that point I set it to 64 as I noticed the beginnings of fermentation. Had a family fun day yesterday and when we got home around 5:30 beer was at 66.9 with active fermentation. Woke up this morning to beer at 68 and I could even hear the constant bubbling(blow off in starsan bowl). Dropped controller to 63 and beer is currently at 67.6.

I have my cold differential set to 3 degrees as i don't want my freezer cycling too much. It was 87 ambient in my garage yesterday so she wanted to kick on a little quicker than I was comfortable with when I had it set to a 2 degree diff.

My goal fermentation temp is 67.5, so this method seems to be working for me. Not to mention it gives me something to tinker with.
So much better than wet t-shirts, ice bowls and crawling in the coat closet

 

[rtracer]

Oops, this was supposed to go in the Fermentation section. Oh well, I am a beginner...

 

[PADave]

Tape the probe to the fermenter. You want the wort to keep temp. Yes the air will undershoot, but it takes much more energy to move 5 gallons of liquid a degree or two than to change the air temp. I use a freezer, tape the probe to the fermenter, and have a 1 degree temp differential. Even during active fermentation the freezer is only running maybe once an hour. I tried hanging in air method once, actually the probe fell off, and the temp control was nowhere close.

 

[rtracer]

Tape the probe to the fermenter. You want the wort to keep temp. Yes the air will undershoot, but it takes much more energy to move 5 gallons of liquid a degree or two than to change the air temp. I use a freezer, tape the probe to the fermenter, and have a 1 degree temp differential. Even during active fermentation the freezer is only running maybe once an hour. I tried hanging in air method once, actually the probe fell off, and the temp control was nowhere close.

Naaa, I'm having great results with the way described above and not planning on changing. Glad to hear your way is also also working.

 

[The_Bishop]

You'll have a far greater stability of wort temperature with the probe attached to the fermenting vessel. Also, you can use a tighter differential, and set the compressor delay for at least 10 minutes. This wilt ensure the longevity of the cooling system and give you the closest control of the wort temperature.

 

[rtracer]

You'll have a far greater stability of wort temperature with the probe attached to the fermenting vessel. Also, you can use a tighter differential, and set the compressor delay for at least 10 minutes. This wilt ensure the longevity of the cooling system and give you the closest control of the wort temperature.

I just don't see how I would have a far greater stability of my beer temp using this method. Through the first three days of active fermentation I Have maintained
My beer within 1 degree.
Also I have two carboys at different stages of fermentation. I like to know that the other carboy not in active fermentation will not go below whatever set temp I have on the controller.

 

[MrBJones]

With the two carboys in the freezer, how much free space is left over? If it's much, reduce it with milk jugs filled with water. You'll get more stability and less cycling.

 

[The_Bishop]

When the probe is attached to the fermenter, it's actually measuring the temperature of the fermenter and controlling it more or less directly.

Do what pleases you; I'm only offering information that has been worked out by a lot more brewers than I.

 

[lawless317]

View attachment ImageUploadedByHome Brew1466699176.574255.jpg

 

[wysiwyg]

I'm in the camp for attaching probe to fermenter, or submerging in a bucket of starsan inside the chamber. Then the set temperature more closely matches the measured temperature. Seems you're sort of guessing right now - set to 63 to ferment at 67ish? You will have much more variability with bigger beers that generate more heat.

I get it, you'll do what works for you, and I'm happy you found a method for controlling temps, but there's a few principles of thermodynamics that may make your process even better.

Cheers!

 

[rtracer]

I'm in the camp for attaching probe to fermenter, or submerging in a bucket of starsan inside the chamber. Then the set temperature more closely matches the measured temperature. Seems you're sort of guessing right now - set to 63 to ferment at 67ish? You will have much more variability with bigger beers that generate more heat.

I get it, you'll do what works for you, and I'm happy you found a method for controlling temps, but there's a few principles of thermodynamics that may make your process even better.

Cheers!

I get the whole attached to the fermenter ideal, and what the thinking is behind it. Putting the probe in a separate water container seems like it would be worst practice of the three options discussed so far.
I would be interested in hearing the principles of thermodynamics you are referring to.

 

[rtracer]

With the two carboys in the freezer, how much free space is left over? If it's much, reduce it with milk jugs filled with water. You'll get more stability and less cycling.

Not much, Its a tight squeeze for my two carboys on the bottom. I have my blow off container on the top rack. I could probably fit a couple on the top shelf to achieve a better "cold sink"
Thanks!

 

[PADave]

I would be interested in hearing the principles of thermodynamics you are referring to.

It's the fact that you are controlling the air temp in the freezer rather than the wort temp. That's why you have a lot of cycling. Simple principle of thermodynamics says it takes a lot more energy to heat a volume of water than the same volume of air. Likewise that same volume of liquid is going to cool much slower than the same volume of air. Sure, when my controller is set to 63 the air temp may get as low as 45 in the freezer when it kicks off. But the wort only is at 63, maybe drops to 62.5. Then on the other end the air might get up to 65 or so before the wort reaches 64. If your freezer is cycling on frequently, you're doing it wrong.

 

[Clavain46]

I'm going a step further, just bought a carboy bung with a thermalwell and when I rack my current brew over to its secondary I'll have my temp probe in the beer. I doubt that it makes that much difference but at least it'll be that much more accurate.

 

[ITV]

I suggest that when your beer is done fermenting that you experiment with the carboy filled with water to see what works best for you.

I built a fermentation chamber similar to yours and put a temp probe inside the water filled fermenter and taped the probe to the outside. I set my temp controller for a 1 deg. differential and a 10 min compressor cycle to prevent short cycling. I adjusted the preset temperature at different temps and recorded the water temp inside the fermenter. I was able to control my temps within 1 deg.

Several batches later I no longer tape the probe to the outside of the fermenter, I now use plumbers putty since it doesn't come off like the tape.

I am also using a Lasko ceramic heater to bring up the temps if needed.

 

[rtracer]

Alright, brewing a batch Monday, I'll try the tape to the carboy method to see how i like it.
My current batch should be done actively fermenting my then so I will not be too worried about its temp by then