Temp swings using ITC 308

[brew703]

I ferment in a SSBT brew bucket and installed a thermo well in the lid.
All settings are 1 degree. Once fermentation starts I normally experience a 2 degree temp swing but today I see a 5 degree swing. I don't use any type of heating but looking for ways to prevent that much of a swing.

For those using the brew bucket and itc 308 do you see a large temp swing? Would insulating the bucket help?
The temp swing is below my set point. Ex: my temp is set at 68 with a 1 degree differential. So the carry over went 5 degrees below my set temp which I've never experienced before.

 

[Jag75]

Are you using a chiller or a freezer to ferment in?

 

[MikeCo]

Where is your temperature sensor? I tape mine to the side of brew bucket covered by some styrofoam to insulate it, and it tracks to one degree F from the digital thermometer in the thermowell. The ITC keeps it very close to target as long as I start with the actual wort temperature within a few degrees of the set temperature. I also keep my heat source (a fermwrap) far enough away from the sensor so the sensor is not seeing a significantly higher temperature than the wort. If your temperature is over/undershooting, I would start with making sure the sensor is located to optimize sensing of the actual wort temperature and is not being over-influenced by the ambient temperature in the chamber or your heat source.

 

[brew703]

Are you using a chiller or a freezer to ferment in?

Freezer

 

[brew703]

Where is your temperature sensor? I tape mine to the side of brew bucket covered by some styrofoam to insulate it, and it tracks to one degree F from the digital thermometer in the thermowell. The ITC keeps it very close to target as long as I start with the actual wort temperature within a few degrees of the set temperature. I also keep my heat source (a fermwrap) far enough away from the sensor so the sensor is not seeing a significantly higher temperature than the wort. If your temperature is over/undershooting, I would start with making sure the sensor is located to optimize sensing of the actual wort temperature and is not being over-influenced by the ambient temperature in the chamber or your heat source.

It's in a thermo well through the lid. Never had that big of a temp swing.

 

[MikeCo]

If it's in a thermowell, all I can think is that the freezer is cooling the outer wort faster than in the center of the fermenter and by the time the probe reaches the set temperature, the majority of the wort is too cool. Can the probe be moved higher to the surface so it's not so far into the mass of the wort?

 

[brew703]

Yea I can adjust it. It's probably about half way into the wort.

 

[MikeCo]

Try that - it should help to get it just far enough into the wort so it's sensing the wort temp near the top. If it still overshoots too much, you may have to try taping the sensor to the outside and insulating.

 

[IslandLizard]

I don't understand why your "temp spread" is so much larger suddenly. Did you change anything in your equipment or your method of temp control?

I agree that using a thermowell close to the center of the vessel can cause (undesirable) long lag times in response to temp changes (freezer air) applied to the vessel's outer mantle. More so when fermentation is not very active, not creating sufficient turbulence to disperse the heat/cold.

For that I prefer to tape the sensor under a piece of packing foam along the side of plastic bucket fermenters.

Now for stainless buckets that may not be the best placement, as the metal is much more temp conductive, creating a bias compared to the content (your beer).

What is your target ferm temp?

 

[brew703]

Nothing has changed- I usually ferment in the 65-68 range. I normally see a 2 degree swing down past my set temp, but never as much as I saw over the weekend. I dont know what would have caused that but it appears to have settled out, or at least I think it did. I work during the day so I cant monitor. But the last couple of days when I get home the temp was within 2 degrees of my set temp.

 

[brew703]

I'll also raise the probe up some to see what the temp difference is. I've always had it about half way down.

 

[CarolinaMatt]

have you tried to calibrate your ITC? I had an issue where I realized mine was having swings all the way up to 10 degrees off. Had to calibrate and adjust. Eventually the issue led to a few frozen kegs and I ended up buying another inkbird.

 

[brew703]

have you tried to calibrate your ITC? I had an issue where I realized mine was having swings all the way up to 10 degrees off. Had to calibrate and adjust. Eventually the issue led to a few frozen kegs and I ended up buying another inkbird.

I calibrated it when I got it about 2 yrs ago. Haven't tried again. Maybe it's time to check it.

 

[CarolinaMatt]

I calibrated it when I got it about 2 yrs ago. Haven't tried again. Maybe it's time to check it.

Give that a shot and let us know what it says.