What do you use to insulate your fermentation chamber temp probe?

[h22lude]

So I have been using the ebay temp controller for a year or so now. I have been taping the probe to the side of my buckets (now carboy) and then putting a folded face cloth over that and using two bungee cords to hold it on. I thought that was working great...until just now. I took my carboy out to dry hop and noticed the temp rose 1°C (which was about 1.8°F). 2°F isn't all that much but if it rose that much after being out for less than 5 minutes, I'm thinking the probe isn't insulated enough. I highly doubt the 5.5 gallons of beer rose 2°F within the 5 minutes.

What does everyone use to insulate their probe? Have you noticed that kind of temp change when taking your primary out of the fridge/chamber?

 

[Kerrbrewer]

I use a piece of pipe insulation and use an ace bandage to hold it to the Carboy.

 

[AK7007]

Thermowell

 

[CU_tony]

I use a few layers of foam packing material, all taped together over the probe on the side of a glass carboy

 

[h22lude]

I'm wondering if my facecloth is just too thin. It is folded twice so I figured it would be fine but that quick jump in temp seemed odd even if it was only 2°F.

 

[tjmac5071]

I use reflectix taped on the side

 

[BlueHouseBrewhaus]

I took a piece of 1" thick styrofoam packing block and carved a groove on one side that just fits my temp probe. I use bungees to hold the block on the side of the fermenter with the groove facing in so the probe slips right in snug against the fermenter in its little styrofoam cacoon. I have checked actual beer temp against my temp controller and it is spot on.

 

[Morrey]

I tape the probe to the keg or fermenter with blue painters tape. Then cover that layer with a neoprene beer coozie securing the coozie with another strip of blue tape. Peels off with no gummy stickiness.

 

[schematix]

I've always used thermowells in the past. Rock solid stable.

Just did my first brew where I am fermenting in corny kegs. I don't have my thermwell lids yet so I just taped it to the keg, then covered it with foam peanuts and a rag.

I have no confidence in it's accuracy or stability. If i crack the lid to the ferm chamber within 15 seconds the compressor is kicking on. Hopefully this is a one time occurrence since i am having some corny keg lids custom built with thermwells that should be here by next brew day.

 

[Erik_Mog]

I use a piece of foam left over from putting in a window A/C unit.

 

[aprichman]

I use a giant sponge meant for washing vehicles and adjustable bungees to hold it in place. Outside of that I use blue painters tape to hold the probe from my ITC-1000 based temp controller.

 

[JohnSand]

Piece of a cheap styrofoam cooler lid.

 

[JONNYROTTEN]

A $15 thermowell.It reads the internal temp,cant get any better then that...No bungie cords,ropes,sponges,insulation or whatever else everyone.Most importantly no wondering if any air is getting in..And zero fussing around with the things listed...This comes from someone who used to go the insulation and tape route until I said to myself.."it's 15 bucks,why am I not just getting it"..and then I did

 

[mongoose33]

Here's how I do it. I carved out a thin channel for the probe to sit in so the foam surrounds it while pressed against the fermenter.

 

[Northbank]

I will never understand why people will spend money on a fridge/freezer, a temperature controller and not throw the extra $20 down for a thermowell so you can get a real reading. No matter how well you insulate the sensor, as your freezer kicks on the glass will cool and even if its not a great conductor it will conduct heat or cold ...

 

[Photopilot]

When i can I buy something with a thermowell on it.

In the past I used an old wash cloth and doubled or quadrupled up. Place the probe against my fermentation chamber place the washcloth up against the probe and use packing tape to hold it in place. If there was a fan blowing or lots of air movement I would put layers of tape over to remove any air movement. I remember testing it compared to the center of the fermenter and found it very accurate.

 

[Photopilot]

I will never understand why people will spend money on a fridge/freezer, a temperature controller and not throw the extra $20 down for a thermowell so you can get a real reading. No matter how well you insulate the sensor, as your freezer kicks on the glass will cool and even if its not a great conductor it will conduct heat or cold ...

I use thermowells but feel you run the opposite concern with them. While no hydrologist here is my theory.

Done right the thermowell may be in the very center of the liquid, which will be the last part to get to temperature. The freezer may be on for a while chilling the vessel and the outer layer of wort before the temp reaches the center. It is possible the chamber, vessel and most of the wort is colder than set temperature before the message reaches the thermowell.

If the outer layer of the vessel is at target temp this temperature will eventually make its way to the center of the vessel without undershooting. Once fermentation starts I would think the movement of the fermentation will keep the temperatures uniform throughout the vessel.

 

[lschiavo]

I use thermowells but feel you run the opposite concern with them. While no hydrologist here is my theory.

Done right the thermowell may be in the very center of the liquid, which will be the last part to get to temperature. The freezer may be on for a while chilling the vessel and the outer layer of wort before the temp reaches the center. It is possible the chamber, vessel and most of the wort is colder than set temperature before the message reaches the thermowell.

If the outer layer of the vessel is at target temp this temperature will eventually make its way to the center of the vessel without undershooting. Once fermentation starts I would think the movement of the fermentation will keep the temperatures uniform throughout the vessel.

This all makes good sense to me. Especially since the most precise temp control is needed during active fermentation where the process so conveniently stirs the beer for us.

The rest of the time a beer is in the chamber is really just a long term ambient control. I doubt it makes any difference where you measure the temp within the chamber. A taped on probe or thermowell are probably about equal at that point.

 

[lschiavo]

I took my carboy out to dry hop and noticed the temp rose 1°C (which was about 1.8°F). 2°F isn't all that much but if it rose that much after being out for less than 5 minutes, I'm thinking the probe isn't insulated enough. I highly doubt the 5.5 gallons of beer rose 2°F within the 5 minutes.

The beer certainly did not rise that much. Probably not even measurably. I'm sure when you put the carboy back in, it was back to temp within a similar amount of time. Taking the carboy out of your chamber is removing it from the controlled environment (the temp in the chamber is part of that environment). You have a system that reacts quickly to that change. Seems like a good thing to me.

Long term stable temps is the goal here. Unless you are seeing an issue with that, I wouldn't change anything. A probe taped to the carboy and insulated with a towel always worked well for me.

 

[Morrey]

I use thermowells but feel you run the opposite concern with them. While no hydrologist here is my theory.

Done right the thermowell may be in the very center of the liquid, which will be the last part to get to temperature. The freezer may be on for a while chilling the vessel and the outer layer of wort before the temp reaches the center. It is possible the chamber, vessel and most of the wort is colder than set temperature before the message reaches the thermowell.

If the outer layer of the vessel is at target temp this temperature will eventually make its way to the center of the vessel without undershooting. Once fermentation starts I would think the movement of the fermentation will keep the temperatures uniform throughout the vessel.

I have considered thermowells, in fact I have a hooded thermowell for a carboy from MoreBeer. BUT, I don't use carboys for primary and have 7.8G fermenter buckets that I use. What do you feel is a way to modify the lid of the pail to add a thermowell? Would you simply drill a hole in the lid, insert the thermowell and seal with some silicone?

If this sounds reasonable, where can I find a thermowell that is just the metal shaft and not part of a hood or similar?

 

[h22lude]

I will never understand why people will spend money on a fridge/freezer, a temperature controller and not throw the extra $20 down for a thermowell so you can get a real reading. No matter how well you insulate the sensor, as your freezer kicks on the glass will cool and even if its not a great conductor it will conduct heat or cold ...

Many people have posted their experiments here on HBT that the difference between a thermowell and taping to the side was 1° when first put into the fridge then the temp difference stabilized once the wort temp stabilized. To me, that is pretty damn accurate.


I think I'm going to try foam insulation next time. I might buy a cheaper thermometer to use to check the temp and see if there are any big swings. I like how cheap and east the STC-1000 build was but after doing some reading it seems like they could allow swings in temp.

 

[Photopilot]

I have considered thermowells, in fact I have a hooded thermowell for a carboy from MoreBeer. BUT, I don't use carboys for primary and have 7.8G fermenter buckets that I use. What do you feel is a way to modify the lid of the pail to add a thermowell? Would you simply drill a hole in the lid, insert the thermowell and seal with some silicone?

If this sounds reasonable, where can I find a thermowell that is just the metal shaft and not part of a hood or similar?

My argument is more for a thermowell being unnecessary in a fermenting vessels. The only reason I have them is conical came so equipped and it was an option for my sanke based lid on my bright tank. Maybe a little bit of bling factor as well, when investing in expensive stainless steel hardware add the extra expense to do it right. It also saves on the packing tape and wash cloth laundering. I have long made my own thermowells in a cooler based MLTs and HLTs.

I am already suspect of plastic fermenters. But have been dissuaded in another thread of my prejudices but still choose not to ferment in them, too many moving parts for my liking. Drilling and siliconing in a thermowell to me just adds another potential source of contamination or air leak. As I saw with heating elements and thermowells in my coolers it is the likely source of early retirement for a vessel. If you feel the need to add a thermowell to a plastic bucket, I would recommend drilling a hole in the lid and adding a perfectly matched grommet to let the thermowell slide in snugly, probably the same setup already on the bucket lid for an airlock would work.

 

[mattdee1]

I just stick my STC probe on the side of my bucket with electrical tape, then cover it with a roughly 4" x 4" piece of packing material... and more tape.

It looks really ghetto, but it works just fine. I've measured the temperature of hydro samples and they've been dead-nuts on to where they're supposed to be.

 

[Jim311]

I use a strap with a buckle similar to what is on most backpacks, so it's adjustable. Then I just put a shop rag over the probe and tighten down the strap. It's real fancy. People are splittin' hairs here. I doubt it matters much whether the outside of the carboy is 1 degree warmer/colder than the inside of it. As long as the temperature is stable and close to where it should be I'm not going to sweat it. I'm a low effort brewer, not a professional bean counter.

 

[h22lude]

I seem to be doing what most others do. Not sure why the odd swing in temp when I took my carboy out. I'll need to try some experiments once this beer is kegged. I'll try different insulation material. Try on a glass carboy and plastic bucket. I'll check the temp with a thermometer and see how close it is to the probe taped on the side. As long as the temp is around what I set it to, I'm happy.

 

[brick_haus]

I tape the probe to the side of the fermenter, cover it with a 6x6 piece of insulation (the stuff under the carpet in your car/house), cover that with foil and seal the outside edges with tape. No air can get to the probe when done properly so, theoretically, it's measuring the temp of the stainless surface of the conical, which should be the same as the liquid in contact with that. I'm sure its close in the beginning and after a day or two it should equilibrate.

 

[thekraken]

The best thing I've used, besides a thermowell, was just padded envelope. That bubble wrap lined envelope stuff you get stuff shipped to you in.

 

[Northbank]

I'm curious now, I want to try both internal and external with my setup and see what the differences are ...

 

[h22lude]

I just remembered that I forgot to add an ounce of Columbus when I added my Galaxy so I did a quick test. I took out my carboy and it rose over 1°C within a minute like last time. It went from 17.9°C to 19.3°C. I took some beer out for a gravity reading and measured the temp. It was 19°C. So my thinking is the probe wasn't insulated enough and was reading a mix of the beer and ambient temp. I found bubble wrap in my garage so I put that over the probe and then put my facecloth over that with two bungee cords. The few minutes I was down in my basement after putting it back in the fridge, it stayed at 18.9°C.

I think this shows that it wasn't insulated well. I wonder how many batches fermented warm because of this.

For S&Gs I may buy a thermowell and test out to see which method is more accurate.

 

[PADave]

I just use some bubble wrap and tape. I know it's reading the temp of the fermenter because sometimes the air temp gets well below the fermenter temp.

 

[h22lude]

I just use some bubble wrap and tape. I know it's reading the temp of the fermenter because sometimes the air temp gets well below the fermenter temp.

This is what I have been doing ever since I got my fridge and was happy with it when using my plastic buckets (this is my first batch with a glass carboy). My only concern with taping it to the side is the probe may read the glass temp which may be different from the beer when the fridge is on.

Could the glass cool down quicker than the beer? I know the beer will take some time to cool down even a degree because of the large mass. Will the glass carboy read a lower temp because it is touching the cold air and isn't as large of a mass?

 

[PADave]

This is what I have been doing ever since I got my fridge and was happy with it when using my plastic buckets (this is my first batch with a glass carboy). My only concern with taping it to the side is the probe may read the glass temp which may be different from the beer when the fridge is on.

Could the glass cool down quicker than the beer? I know the beer will take some time to cool down even a degree because of the large mass. Will the glass carboy read a lower temp because it is touching the cold air and isn't as large of a mass?

But the glass is also touching the warmer beer. Honestly, once my wort gets down to the set temp, and everything stabilizes, my freezer only kicks on maybe once every hour or two during active fermentation. Then after fermentation is done, a few times a day. Once temps are stable they hold within a degree or two.

 

[m1k3]

I have drilled my bucket lids with a stepped bit to accept the MoreBeer Thermowell that is mounted to a stopper. I fill the thermowell with StarSan to ensure i am getting the temp of the liquid and not any air inside the termowell.

That being said I've put the probe on a second controller with the probe on the side of the bucket covered with cardboard and it's virtually the same reading.

I believe that you will make great beer with either method.

 

[mattdee1]

This is what I have been doing ever since I got my fridge and was happy with it when using my plastic buckets (this is my first batch with a glass carboy). My only concern with taping it to the side is the probe may read the glass temp which may be different from the beer when the fridge is on.

Could the glass cool down quicker than the beer? I know the beer will take some time to cool down even a degree because of the large mass. Will the glass carboy read a lower temp because it is touching the cold air and isn't as large of a mass?

If left alone, the temperature of the beer and container will tend toward the control temperature over the course of a few hours. Once there, only some kind of temperature disturbance will upset the balance. For example, opening the fridge/freezer and letting in hot summer air while you monkey around with a wine thief might temporarily elevate the probe reading and trigger the compressor to kick on. But as soon as the fridge is closed again, the temperature read by the probe will quite quickly settle back to a reading more indicative of the beer temperature. The few minutes that the compressor ends up running to get there (if at all) will have very minimal impact on the temperature of 5-10 gallons of beer.

IMO, the main reason for insulating the probe is to prevent unnecessary cycling of the compressor on your fridge when you open the door. Very basic probe insulation and compressor delay setting of 10 minutes on the STC is enough to keep that problem at bay.