Freezer too cold even with temp controller

[Nosybear]

I'm guessing it's the mass of the beer causing the problem for a couple of reasons: First, simple thermodynamics. You're cooling a large mass of liquid using air. By the time the liquid drops to the temperature you desire, you've way undershot the actual temperature needed to hold it there (assumption, the probe is in contact with the beer). Or you've cooled the air to the point your controller kicks the freezer off but your beer is not cooled to the proper temps (assuming you're measuring the temperature of the air in the freezer or, as you mention, a smaller volume of liquid). I use the Inkbird controller in my fermenting refrigerator with an incandescent light to balance with the probe in the beer. By the time the beer has stopped producing its own heat due to fermentation, all the yo-yoing of the temperature has stopped and everything is near equilibrium.

By the way, use the Inkbird in celsius rather than Fahrenheit mode - it's more accurate and the temperature range is closer.

 

[jeffpn]

By the way, use the Inkbird in celsius rather than Fahrenheit mode - it's more accurate and the temperature range is closer.

Would you mind elaborating on that point? I'm curious how you came to that conclusion.

 

[Nosybear]

For mine, in Fahrenheit mode, the upper and lower limits are 1 degree F from the set temperature (the Difference Set value) for a range of 2 degrees F. In Celsius mode, the limits are 0.3 degrees C, giving me a 0.6 degree C range. One degree Fahrenheit is 0.54 degrees Celsius, narrowing the range from two degrees F in Fahrenheit mode to a bit more than one degree F in Celsius mode. The accuracy of these values is still +/- 1 degree, but the range is smaller in Celsius mode.

 

[jeffpn]

That's interesting. I'm guessing your controller is related, maybe even identical, to my STC-1000 controllers that I have. They look the same. Mine are celcius only. I have my kick point set to the minimum possible of 0.3° like you mentioned. I read up on flashing them, but I'm not that into electronics. That surprises me that it's a full 1° kick if you go Fahrenheit.

Edit: when I looked up an Inkbird controller, I zeroed in on one that looks like my STC-1000. I see they have a different controller as well, which of course is pictured in the first post of this thread. It wouldn't surprise me if the programming is the same between the two units.

 

[i drink to forget]

So I have an InkBird temp controller for a new chest freezer I picked up. I ran a test on it with the temp controller and the temp continues to drop long after the shut off. I have the probe in a bottle of water. As a test set temp, I set it at 38F with a diff of 1. It cuts off when its supposed to but the temp continued to drop to 31F. The reason I chose this InkBird is because it accepts both a cooling and heating device simultaneously and switches between the two to help maintain the temp. My concern is if I cannot stabilize the temps on just the cold side within a few degrees, the wort may get too cold to even begin the fermentation to produce any of its own heat. Suggestions, folks?

The air in the freezer is getting cooled to the point you set. however as the probe is in water the water is acting like a buffer and takes a while to cool down to the surrounding air temp. meanwhile hard working old mr freeze is chugging away cooling down to arctic winter as hes not been told to stop by the happily warm probe in the water. by the time the probe feels the chill the air outside is colder than a polar bears cold bits and so despite the fact mr freeze has stopped piling on the chills the air temp is still way too cold and continues to cool the bottle even though nothing is happening.

I would suggest keeping the probe in the air as the air is what is chilling the wort and there will be minimal lag. i dont imagine the diff will be much and you could always adjust for this.
Do you have a heating device connected out of interest? dont really see that one would work well or be nescessary at all unless the ambient air temp gets significantly below your required range.

 

[i drink to forget]

So I have an InkBird temp controller for a new chest freezer I picked up. I ran a test on it with the temp controller and the temp continues to drop long after the shut off. I have the probe in a bottle of water. As a test set temp, I set it at 38F with a diff of 1. It cuts off when its supposed to but the temp continued to drop to 31F. The reason I chose this InkBird is because it accepts both a cooling and heating device simultaneously and switches between the two to help maintain the temp. My concern is if I cannot stabilize the temps on just the cold side within a few degrees, the wort may get too cold to even begin the fermentation to produce any of its own heat. Suggestions, folks?

The air in the freezer is getting cooled to the point you set. however as the probe is in water the water is acting like a buffer and takes a while to cool down to the surrounding air temp. meanwhile hard working old mr freeze is chugging away cooling down to arctic winter as hes not been told to stop by the happily warm probe in the water. by the time the probe feels the chill the air outside is colder than a polar bears cold bits and so despite the fact mr freeze has stopped piling on the chills the air temp is still way too cold and continues to cool the bottle even though nothing is happening.

I would suggest keeping the probe in the air as the air is what is chilling the wort and there will be minimal lag. i dont imagine the diff will be much and you could always adjust for this.
Do you have a heating device connected out of interest? dont really see that one would work well or be nescessary at all unless the ambient air temp gets significantly below your required range.

so i should probably read what others post before wasting everybodys time.