Keezer cycling more often than expected?

[Dr_Horrible]

Today I kegged my first batch of homebrew. I did all the steps laid out by my previous post and got it all setup and put it in the keezer. Using a Johnson A419, I set it for 40F, +/- 1* differential, with an anti-cycle timeout of 10 min. I set the probe dangling in the keezer about 1 foot up from the bottom and a few inches from a keg.

Along with my 5G batch, I have a 5G keg in there filled to the top with cleaner to add more thermal mass to the contents

It appears that it's turning on every 10-15 minutes for about 5 mins, despite being at an ambient 40F. Based on previous posts, this seems to be more often than others (where I've read that it kicks on maybe once an hour).

I don't know if perhaps I'm having thermal issues, or maybe it's still leveling out the temperature in there? Is it possible that the two kegs are still raising the ambient temperature and haven't reached equilibrium? I admittedly don't know what to expect as this is my first time. Perhaps I'm being too paranoid and need to wait another day or so for equilibrium to be reached inside?

I felt pretty confident in my insulation, as I used 1.5" wood backed by 1.5" foam insulation, sealed with foil tape.

Let me know if this is expected or if I should start thinking about next steps for better insulation.

 

[coolharry]

I'd try to get that probe situated a bit better. I keep a growler full of water in mine and tape the probe to the outside with a bit of insulation.

 

[Dr_Horrible]

I'd try to get that probe situated a bit better. I keep a growler full of water in mine and tape the probe to the outside with a bit of insulation.

What about just a plastic OJ container filled with water? I can tape a probe to that. I've seen some people mention they dunk their probe in water (which isn't what you're suggesting) - I've considered it but I've heard that some probes can screw up in water.

 

[day_trippr]

I set my controller differential to 1°F and during this time of year my keezer will cycle on a roughly 3 hour period, with a roughly 78-83°F ambient (the keezer is in space that we typically don't bother to air condition).

I picked up some 2'x2" velcro straps from either HD or Lowes, and use one of those to pin my temperature probe to the side of the keg about a third of the way from the bottom, with a 6"x4" chunk of inch thick closed cell foam over the probe. So, I'm attempting to control the temperature of a fairly large thermal mass, rather than the air inside the keezer. The hysteresis provided by that thermal mass is what extends the cycle time.

fwiw, it's a rare probe that claims absolute immersion capability, and to my knowledge none of the popular controllers come with such a probe...

Cheers!

 

[Dr_Horrible]

Okay so it sounds like relying on ambient temperature isn't the best idea if I want to minimize cycles. The greater the thermal mass of what the probe is measuring, the less cycling I should have. Seems to make sense. Only issue is that if the probe is measuring a keg that will soon be empty, then the thermal mass and reliability of the probe on that particular keg drops, right? So I'll need to switch it around sometimes.

 

[day_trippr]

You got it. And I do have to move the keezer probe to the fullest keg as the previous keg gets below ~half filled.

I do avoid immediately moving the probe to a fresh keg because there is a few degree differential between my cold-holding/carbonation fridge and my keezer. So tracking a new keg would cause the old kegs to chill down to where a lot of character would be hidden 'til a pour warms up - and I really like that first sip of a freshly poured pint.

We keep white wines in that fridge as well and the spousal unit prefers her whites a little warmer than I like my beer so that differential is there to stay. Just means slightly more frequent probe moves...

Cheers!

 

[wilserbrewer]

I think a 1 degree differential is too low, the kegs of beer have much more mass and will not fluctuate much if any compared to the rest of the keezer. Also realize you loaded 80 lbs of warm liquid into the keezer and it will need to run it's ass off for a day to drop the temp of all that liquid.

I wouldm't be too concerned with the insulation of the collar, with such a minor temp difference to ambient.

I just wrapped the temp probe in a wad of paper towel and plastic wrap to buffer the temp swings in the keezer, but in a fermentation application it should be insulated against the fermenter or better yet in a thermowell to actually represent the temp of the beer.

 

[number40fan]

I zip-locked my probe and stuffed it into a glass of water. I have my STC set to kick on at 39° and shut off at 36°.

 

[Dr_Horrible]

I went ahead and layered a towel with duct tape against a keg and shoved the probe in there for now. I will modify the differential to 2* to help as well