SS Brewtech Chronical, thermowell

[Razorback_Jack]

Hello everyone,

I’m currently fermenting the first batch for which I’ve used the SS Brewtech Chronical, and the FTSs. It’s a Kölsch, using Safale US-05. If you’re familiar with this equipment, you know that both the fermenter AND the FTSs lid have thermowells. I also purchased a Brewtech thermometer to put in the thermowell in the fermenter body, so I could have two readings.

So, the readings from the two thermowell are usually very different. Once I realized this, I moved the FTSs probe to the thermowell on the side, rather than in the lid. Thought this would give me a more accurate reading of my beer’s temp while it’s fermenting. Y’all agree? So the probe (attached to pump system) reads about 65-66, and the probe in the FTSs lid (not attached to pump) sometimes reads 6 degrees higher... 72 or even 73. Am I right to be focused on the probe in the fermenter’s side and not the lid?

Thanks once again for all guidance and suggestions. As I’ve gotten back into brewing after years off, I have forayed into all-grain, stainless steel, and kegging all at the same time. I’m sometimes overwhelmed with what I don’t know.

cheers, and stay safe!
Jackson

 

[pvpeacock]

I noticed the same differences but usually only after transferring warm wort into the fermenter and using the FTS coil to cool the wort to pitching temperature. If I swirled the wort by rocking the fermenter, the two temperatures would eventually equalize to the same temperature. However, I recently bought the FTS controller mounting brackets because I bought a glycol chiller and needed the controller closer to the chiller. See https://www.ssbrewtech.com/products/ftss-controller-mmounting-bracket
As a result, I stopped using the thermowell in the lid and replaced it with one of these plugs. https://www.ssbrewtech.com/collections/accessories/products/17-mm-chiller-coil-hole-plug Now, I only use the thermowell in the body of the fermenter.

 

[Brooothru]

Hello everyone,

I’m currently fermenting the first batch for which I’ve used the SS Brewtech Chronical, and the FTSs. It’s a Kölsch, using Safale US-05. If you’re familiar with this equipment, you know that both the fermenter AND the FTSs lid have thermowells. I also purchased a Brewtech thermometer to put in the thermowell in the fermenter body, so I could have two readings.

So, the readings from the two thermowell are usually very different. Once I realized this, I moved the FTSs probe to the thermowell on the side, rather than in the lid. Thought this would give me a more accurate reading of my beer’s temp while it’s fermenting. Y’all agree? So the probe (attached to pump system) reads about 65-66, and the probe in the FTSs lid (not attached to pump) sometimes reads 6 degrees higher... 72 or even 73. Am I right to be focused on the probe in the fermenter’s side and not the lid?

Thanks once again for all guidance and suggestions. As I’ve gotten back into brewing after years off, I have forayed into all-grain, stainless steel, and kegging all at the same time. I’m sometimes overwhelmed with what I don’t know.

cheers, and stay safe!
Jackson

I agree that the side-mounted thermowell should give a more accurate picture of the true temperature, for a couple of reasons. First, temperature can vary vertically through the beer column due to stratification inside the fermenter and would be noticeable with a top-mounted thermowell. This can also happen in the horizontal axis as well, especially during the active early stages of fermentation, when there are convective currents circulating from the heat generated by the yeast as they metabolize the wort sugars. But the biggest reason I believe the side-mounted thermowell is more accurate is that it is completely submerged in the wort about midway between the bottom and the top of the vertical wort column. At worst it is giving you an average of the rising and descending temperatures of the fermenting wort inside that vertical column. It's my understanding that the temperature can vary several degrees from the rising column to the descending one, but not the 7~9 degree delta you are seeing between top mount and side mount.

Unlike the side-mounted thermowell, the top-mounted thermowell is not completely submerged in the wort, even if you we able (or foolish enough) to fill the fermenter all the way to the brim. The "capacity" may be 7 gallons, but the practical limit is really something about 3~4 quarts less. So part of the thermowell is not exposed to the temperature of the wort, but rather the mixed gasses inside the fermenter on top of the wort. The thermal mass of the wort is much higher than that of the gas layer on top of it and will conduct heat away from the metal in the thermowell much more efficiently than from the gasses above it which will result in inaccurate temperature readings.

I'll add one important caveat. My Chronical was originally configured with the cooling coil on the flat lid. In order to utilize a domed lid I had to modify the fermenter by relocating the coil on a side mount opposite the thermowell. After drilling and repositioning the coil, I noticed that it was coming in contact with the thermowell which would mean the coil would be 'chilling' the thermowell and giving a false reading. I had to gently (and carefully!) bend the coil slightly to one side to create about a 1" gap between the thermowell and the coil. Those temperatures would probably have been off by at least 8~10 degrees if I had not, since the delta between the temperature of my glycol (28F) is 6 degrees colder than the coldest temperature I get inside the Chronical (34F), due to insufficient insulation on the fermenter and the glycol lines, though I seldom lager in either the Chronical or Unitank so the inability to cool past 34F isn't an issue for me. But accurate temperature indications and consistent temperature are for both lagers and ales.

Just make sure that the metal tip of the probe inside the thermowell is pushed in all the way and making contact with the metal in the thermowell. It's also a good idea to stuff a little piece of a wadded up paper towel inside the thermowell opening to help insulate the probe from outside temperatures. Enjoy your Chronical. It took me nearly 25 years of brewing in plastic and glass before I took the plunge into stainless. The improvement in the quality of my beers and the enjoyment of this hobby have grown exponentially since I did. Cheers!

Brooo Brother