Inkbird Setup (for fermentation chamber)

[MrBJones]

As mentioned in another post, I'm now the proud owner of a 7.2 cf chest freezer ($129 at Costco, after $20 immediate rebate). Just read the instructions for the Inkbird I bought a couple weeks ago; the setup process seems to be pretty straightforward, but what values to use? In particular - and assuming standard ales -

• What do you use for Cooling and Heating Differentials...is one degree going to result in excessive of cycling?
• What about Compressor Delay...what will adequately protect the compressor, without compromising cooling?

Thanks, as always!

 

[day_trippr]

I always set compressor delay to its maximum, which is often only 10 minutes.
But if you meter the beer and not the air, you'll never kick off a compressor delay aside from return from a power blackout.

As for differential, I use 1°F. If you meter the beer and not the air, you can get away with that...

Cheers!

 

[RM-MN]

As mentioned in another post, I'm now the proud owner of a 7.2 cf chest freezer ($129 at Costco, after $20 immediate rebate). Just read the instructions for the Inkbird I bought a couple weeks ago; the setup process seems to be pretty straightforward, but what values to use? In particular - and assuming standard ales -

• What do you use for Cooling and Heating Differentials...is one degree going to result in excessive of cycling?
• What about Compressor Delay...what will adequately protect the compressor, without compromising cooling?

Thanks, as always!

If you only measure the air temperature in the freezer, yes it would cause excessive cycling but your beer will take quite a while to change temperature by one degree so by fastening the sensor to the fermenter and insulating it you damp out the temperature changes. With that in mind, why only 1 degree? Fermentation temperature isn't that critical that it needs to be held that close. 2 or 3 degrees difference won't hurt the beer.

 

[Shwagger]

A thermowell into your fermenter, then the probe into the thermowell, wrapped with something to insulate, works wells. Maybe even some thermo grease if you want. It's not critical and KISS

 

[auburntsts]

A thermowell into your fermenter, then the probe into the thermowell, wrapped with something to insulate, works wells. Maybe even some thermo grease if you want. It's not critical and KISS

Wait, I'm confused. If the probe is on the outside of the fermenter I get insulating it against the ambient air temp, but if you are putting the probe into a thermowell so that it's inside the fermenter why would you insulate it?

 

[Shwagger]

Why not? I use bubble wrap around where the opening to the thermowell is. Might help, might not.

 

[auburntsts]

Why not? I use bubble wrap around where the opening to the thermowell is. Might help, might not.

Not saying it's good or bad, I simply don't understand the necessity. Are there reading issues caused by not insulating the probe in the thermowell? And to be clear you are insulating the thermowell opening by closing off gaps between the well and the cord and not the probe itself, correct?

 

[Shwagger]

I am just blocking the opening of the thermowell, so the probe and wire are loosely in there. Not sure if it does anything to be honest, but I like to think it keeps air from circulating into the thermowell.

If I had any thermo grease, I'd fill the thermowell with it to completely insulate the probe. Water would probably work but I'd have to figure out a way to keep it from spilling out of the thermowell. But then again, the probe is not and cannot be permanently fixed into the fermenter.

 

[PADave]

I use 1 degree for cooling while actively fermenting and I set the heat differential at 10, just to keep it from coming on. No need for heat while fermentation is going on, the yeast provide plenty of that. Once active fermentation settles down and I want to raise the temp, I just raise the set temp and let it rise itself. Only time I use heat is in the winter when I want to raise the temp to finish out fermentation. My basement gets pretty chilly in the winter, otherwise no need for heat in the summer.

Compressor delay set to the max. If you got your temp probe measuring the wort, the freezer should only kick on once an hour or so, if that. If the freezer is cycling on and off often you are not getting a good wort temp reading, or the heater and freezer are fighting each other.

 

[MrBJones]

Thanks for the replies!

I've set it up with differentials of one degree. Been testing it - cooling only- with a carboy containing five gallons of water (probe taped to carboy, with bubble wrap over it). The compressor comes on at one degree above the set point, and turns off at the set point. But then the temperature creeps down to 0.8 degrees below the set point before slowly coming back up. Is that good enough?

 

[Jwin]

Also, with a freezer, set the internal thermostat to it's warmest position
IMO, freezers are great friends kegs and horrible for fermentation. To easy to overshoot. Definitely don't want a thermowells in a freezer. By the time your wort drops a degree, ambient is in the 40s or lower. Honestly, before I got my fridge, I found that regulation of the air was easier. I'd set it for a few degrees below target fermentation temp and 3-4 degree differential. Max compressor delay. I kept another thermometer in my thermowell, just to monitor. Temps were stable within a couple of degrees.
Now, I ferment 12g at a time, so I do have more thermal mass to deal with so your mileage may vary.
But, in my experience with freezers, thermowells are good for monitoring, not regulating.
Refrigerators are different due to the difference in temperature extremes.

Ultimately, it will probably take some trial and error for you to find what works best. Start with the probe insulated and taped. Keep an eye on it for overshoots in the first several hours of active fermentation.
Also, if you can, see what ambient temperature is when it is ending a cooling cycle and turning the freezer off. If you have a 20+ degree differential, you need to rethink your approach.

 

[PADave]

Thanks for the replies!

I've set it up with differentials of one degree. Been testing it - cooling only- with a carboy containing five gallons of water (probe taped to carboy, with bubble wrap over it). The compressor comes on at one degree above the set point, and turns off at the set point. But then the temperature creeps down to 0.8 degrees below the set point before slowly coming back up. Is that good enough?

Yes, that is perfect. Like I keep saying, the yeast will be generating heat, going to be a little different with fermentation going on than with just a jug of water.

 

[PADave]

Also, with a freezer, set the internal thermostat to it's warmest position
IMO, freezers are great friends kegs and horrible for fermentation. To easy to overshoot. Definitely don't want a thermowells in a freezer. By the time your wort drops a degree, ambient is in the 40s or lower. Honestly, before I got my fridge, I found that regulation of the air was easier. I'd set it for a few degrees below target fermentation temp and 3-4 degree differential. Max compressor delay. I kept another thermometer in my thermowell, just to monitor. Temps were stable within a couple of degrees.
Now, I ferment 12g at a time, so I do have more thermal mass to deal with so your mileage may vary.
But, in my experience with freezers, thermowells are good for monitoring, not regulating.
Refrigerators are different due to the difference in temperature extremes.

Ultimately, it will probably take some trial and error for you to find what works best. Start with the probe insulated and taped. Keep an eye on it for overshoots in the first several hours of active fermentation.
Also, if you can, see what ambient temperature is when it is ending a cooling cycle and turning the freezer off. If you have a 20+ degree differential, you need to rethink your approach.

The freezer thermostat really has no bearing if using a temp controller. A freezer doesn't cool faster if it's set at the coldest, or cool slower if set at the highest. All the thermostat tells it is when to shut off. Liquid has a much greater thermal mass than air, monitor the wort temp, don't worry about the air temp.

 

[RM-MN]

Thanks for the replies!

I've set it up with differentials of one degree. Been testing it - cooling only- with a carboy containing five gallons of water (probe taped to carboy, with bubble wrap over it). The compressor comes on at one degree above the set point, and turns off at the set point. But then the temperature creeps down to 0.8 degrees below the set point before slowly coming back up. Is that good enough?

Your yeast has a range of temperature that is recommended. It is quite a wide range for most yeasts, like 10 degrees. As long as you can keep the beer within that temp range your beer will turn out OK. Maintaining it closer to the low end of the range usually gets you a cleaner taste. I don't even try to keep it closer than 2 to 4 degrees.

 

[Jwin]

The freezer thermostat really has no bearing if using a temp controller. A freezer doesn't cool faster if it's set at the coldest, or cool slower if set at the highest. All the thermostat tells it is when to shut off. Liquid has a much greater thermal mass than air, monitor the wort temp, don't worry about the air temp.

The reason for the thermostat is a failsafe. If something happens to the probe, *maybe* the beer won't freeze.
Liquid having a greater thermal mass was part of my point. In a freezer, by the time the liquid drops a degree, what temp is your freezer? Not arguing wort vs air. It's very possible to make great beer either way. I suppose there are two big variables, how fast the freezer cools and how big your batch is. In my case, my freezer and 12g in a Speidel, using a thermowell with my inkbird caused overshoots. If floced 002 out about 10 points early on a FW Double Jack clone. Once I moved to a fridge, using the freezer as a keezer, the thermowell worked great. My guess is the large mass, plus the R value of a Speidel coupled with the pace of cooling of the freezer were to blame.
Different strokes.