Johnson Temp Controller A419

I just got my temp controller for my Keezer today and I am not really sure how to use the probe for best results. I searched the forums and there are some threads but a lot of them are older. I first put water in a glass bottle and submerged the probe but then freaked out when I saw threads that said the probes were not water proof. I now just wrapped the probe in a single layer of bubble wrap and wedged it between two empty kegs. I don't have anything in there yet but I am trying to set the temp to 67 for fermentation of my two wheat ales that I currently have sitting in my hall closet. I want to make sure the temp is right before I put my fermenting beer in there and mosey on off to work tomorrow only to come home to frozen wort. I heard the gel pack theory but I don't currently have one and that's all I have heard that sounded good. I ordered a kit from Midwest the other day so I believe there will be a gel pack in there for the yeast I could use. One good idea I heard was using a prescription bottle and filling it with the gel and drilling a hole in the top for a probe. I thought the submerged in water idea was the easiest but I am worried it will mess up the probe. What are you guys doing with your probes...lol

If the goal is to keep the beer at a certain temperature, then you want to monitor the beer. Trap the probe against the side of your keg or carboy with a chunk of insulation, set your desired temperature with a couple of degrees of differential, and you're good to go.

I have two fridges and a keezer supporting my humble brewing efforts, and this is how they all operate...

Cheers!

I order all my brewing ingredients from Austin Home Brewing, and when they ship their yeast they add a gel cold pack. My temperature probe is sandwiched between two of these gel packs with a rubber band holding them together. I added a glass of water for testing and used my digital thermometer, I use for mashing, and the temperatures were identical to the Johnson temperature.

I used to just use the ambient air temperature and the freezer, and the freezer would turn on every fifteen minutes to cool. Now just 3 times every 24 hours. My energy bill is thankful.

I have mine in water with no issues.....

Thanks for the suggestions! The gel packs seem to be the way to way I guess.

Silver - how long has yours been submerged? I feel like short term that is fine but I worry about long term the water making its way in and ruining it

Also have another question, where do you set the temp controller on the actual freezer. I have it set to the coldest setting but I think it drops the temperature too fast. I have the Johnson controller set to 67 but when I went out to check it this morning the read out said 60.

I have 2 submerged, one for over two years. Keezer probe has been in water for 26 months, fermentation fridge has been in water for 6+ months. I didn't realize they couldn't be, whoops LOL

I have been trying to figure out what to do with my probe too. Water could cause build up or be corrosive I guess, but I see others have used it with no problems, so maybe it is not too bad. Tapping to the keg seems great, but I do not like the idea of tapping it over and over. How about a pill bottle with just air in it? The gel in the bottle sounds interesting too, but I am not sure what that would do to the probe in the long run either. Hmm still confused lol.

Get yourself a thermowell and put it into a bottle with water. You don't want to tape it to your keg because of the differential setting on your
A19. You want your keg temp to remain constant temps.

Just wedge it between two smaller thermal masses.

Well I ended up taping it to the side of the car boy and covering it in a few layers of bubble wrap. Since then them temp has been pegged right at 66 and hasn't moved. Looks like I am going with this method for now. Not sure what I'll do when there are kegs in there but I might go with the gel. Don't want to have to replace this thing for a while

they are usually pretty reliable. most of us don't have problems with our johnson's.

For a slightly different perspective, I have it measure the air temperature of my kegerator (which doubles as my fermentation chamber), but have the differential set higher (6-7 degrees, I think). Because of the thermal mass of the beer, I find that I can dial-in my keg temps this way without the beer actually changing temp (as confirmed by my thermapen).

If I try to measure the temperature of the beer with the probe, the whole thing will go up 2 degrees before the compresser kicks on (if I understand it correctly), then go down two degrees before it kicks off (which is a long time running the compresser). Changing the air temps over a shorter cylce leads to a more conssistent beer temp, but also takes a little practice to dial-in. Different strokes.

chally said:

For a slightly different perspective, I have it measure the air temperature of my kegerator (which doubles as my fermentation chamber), but have the differential set higher (6-7 degrees, I think). Because of the thermal mass of the beer, I find that I can dial-in my keg temps this way without the beer actually changing temp (as confirmed by my thermapen).

If I try to measure the temperature of the beer with the probe, the whole thing will go up 2 degrees before the compresser kicks on (if I understand it correctly), then go down two degrees before it kicks off (which is a long time running the compresser). Changing the air temps over a shorter cylce leads to a more conssistent beer temp, but also takes a little practice to dial-in. Different strokes.

Click to expand...

Bingo.

If you've got the temp probe taped to your fermenter it's going to swing in temps to what ever you have your differential set at.

I have mine in a bottle of water using a thermowell.