temp probe outside or in fermenter?

Australia & New Zealand Homebrewing Forum

Help Support Australia & New Zealand Homebrewing Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
superstock said:
Do you guys just slide your temp sensor into the thermowell dry?
Mattress said:
It's not like we get all super anal about our processes. :D
superstock said:
I totally agree with you. Against the FV wall, insulated & taped does me.
Based on the current trend this topic is taking... that's a little too much information. But hey, whatever rocks your fermenting fridge. B)
 
Im doin it a littleeee different and using a stainless K-type thermocouple thats secured into my fermenter. Bit more contact and accuracy over a thermowell and less movement than just chucking it in the wort! Works for me ImageUploadedByAussie Home Brewer1408540195.364455.jpg
 
If you use yeast slants, you can clean one out drill small hole in top lid. Then fill slant with water and replace cap with your probe poking through it into the water and afix to side of fermenter with tape. This insures you dont get fridge turning on frequently and possibly damaging fridge and using more power than necessary ( that is if you connected a pid temp controller to turn fridge on and off). The minimum amount of water should be enough so as not to over or under shoot your temps. This is what I have done.

Good luck
 
mofox1 said:
Based on the current trend this topic is taking... that's a little too much information. But hey, whatever rocks your fermenting fridge. B)
Guys, are we still doing phrasing?
 
I must be the only one that just throws the probe under the glad wrap and seal and lets it float around in the middle of the fermenter.
 
I concur, how sure are you that the K-type thermocouple is reading correctly at that range nathanvonetc.? They're known to be out by +/-2°C. I use them for my HERMS and have to check how much they are out every brew so I can accomodate for the error.


Hawko777 said:
... This insures you dont get fridge turning on frequently and possibly damaging fridge and using more power than necessary ( that is if you connected a pid temp controller to turn fridge on and off). ...
Take a lof of care using PID controller on a fridge. Unless it is purpose-made for fridge control, it's a fast way to kill a compressor. This includes the mounting arrangement you're suggesting. A thermostat or STC-1000 type controller is far more suitable.
 
Using a fridge with a time-proportional PID controller is pretty much the worst idea ever if you don't know what you're doing. These PID controllers turn the output onffor a percentage of a nominated time, eg 2 or 10 seconds for an immersion heater. This is obviously not that flash for a fridge to be turning on fur 0.4 seconds every 2 seconds. I guess you could make this 5min fur the freezer/fridge. If you had a variable frequency drive on the compressor and a 0-100% output, that would be cool.

There are smarter on/off controllers that measure rate of change and then roll off the cycles. The most obvious example is BrewPi. I'm sure there are others out there.
 
Adr_0 said:
accuracy?
TheWiggman said:
I concur, how sure are you that the K-type thermocouple is reading correctly at that range nathanvonetc.? They're known to be out by +/-2°C. I use them for my HERMS and have to check how much they are out every brew so I can accomodate for the error.
really accurate actually! i use an Atkin's Aquatuff which provides a plus or minus 0.3*c accuracy at ambient temperatures, the probe is a cheap one and the cable to the connectors a bit long so the reading is slightly delayed but this is no issue for the relatively slow moving temps of fermentation, tested it in ice water compared to the short high-quality probe that came with the unit and got the same reading to a degree with only 0.2 difference.
 
I used to tape mine to the side until I couldnt be bothered anymore. Now I just place it into the wort under gladwrap and I have found my temp is so much more stable than previously. Just a spray with sanitiser and a few wipes a couple of times and shes been good. Touch wood :)
Macca
 
Revelation: taping to the side of a fermeter doesn't do a great job for me. ACTUAL REAL-LIFE PIC OF FERMENTER SHOWN BELOW -

IMG_3227.JPG

I scored this fridge last week which has an internal circulation fan - perfect (found on the side of the road, the owner said "it's no good, it freezes things all the time and we couldn't fix the temp adjuster thing". Whimmy-wham!).
  • I set my STC-1000 to 10°C for my pilsner. Yeast nutrient, 02 for 1 min. Noted activity after 12h.
  • Day 2 - not much action. Check SG which had dropped 3 points. Bumped temp to 11°C
  • Day 3 (yesterday) - just beginning to see krausen.
I've noticed that the 'new' fridge seems to run a lot for a fridge trying to achieve 11°C.
Considering it should be well underway by now I put a glass (which you can see in the pic) next to the fermenter with my thermometer in it. I left it for a few hours and came back to see it sitting at 6°C. As far as I'm concerned the two liquids should be the same because the air is being recirculated. This explains the slow start, and I gave the pilsner a gentle stroke to show my appreciation that even though it was at 6°C, it was still fermenting.

I had my STC-1000 adjust to +1 so in effect it was set to 10°C, but still controlling 4°C lower than set value. To account for this I've adjusted the offset but it goes to show that it's hard to trust the sensor if it's not submersed.

Yes, I have checked the accuracy of the STC temp probe with my thermometer before and yes, I will be buying a submersible probe tonight. Life's too short to gamble with pilsners.
 
superstock said:
Do you guys just slide your temp sensor into the thermowell dry?
Most thermowell controlled devices in industry have oil/liquid in the thermowell to transmit temp more directly, accurately and responsive to the sensor.
Great idea, but my impression with the temp mate probes I have is that they're more splash resistant than water proof.

I use option e) lid with SS thermowell (from beer belly)

The thermowell is positioned halfway between the wall and centre. Figure this gives a more average reading. And about a third to half way up from the bottom. Depending on depth of fermenter.

I slide the thermowell through the grommet lubrucated with starsan, but try to keep the thermowell dry (ish) on the inside. It invariably has some starsan in it. In the past I was not so careful and my probes (they're not rubber like Stc probes) show signs of verdigris/corrosion.

I use a heatbelt placed wrapped around above the tap, and have found this corrects for heating overshoot compared to just using a heater in the fridge cavity. Could perhaps be solved with a PID, but I already have temp mates/stcs
 
TheWiggman said:
Revelation: taping to the side of a fermeter doesn't do a great job for me. ACTUAL REAL-LIFE PIC OF FERMENTER SHOWN BELOW -

attachicon.gif
IMG_3227.JPG

I scored this fridge last week which has an internal circulation fan - perfect (found on the side of the road, the owner said "it's no good, it freezes things all the time and we couldn't fix the temp adjuster thing". Whimmy-wham!).
  • I set my STC-1000 to 10°C for my pilsner. Yeast nutrient, 02 for 1 min. Noted activity after 12h.
  • Day 2 - not much action. Check SG which had dropped 3 points. Bumped temp to 11°C
  • Day 3 (yesterday) - just beginning to see krausen.
I've noticed that the 'new' fridge seems to run a lot for a fridge trying to achieve 11°C.
Considering it should be well underway by now I put a glass (which you can see in the pic) next to the fermenter with my thermometer in it. I left it for a few hours and came back to see it sitting at 6°C. As far as I'm concerned the two liquids should be the same because the air is being recirculated. This explains the slow start, and I gave the pilsner a gentle stroke to show my appreciation that even though it was at 6°C, it was still fermenting.

I had my STC-1000 adjust to +1 so in effect it was set to 10°C, but still controlling 4°C lower than set value. To account for this I've adjusted the offset but it goes to show that it's hard to trust the sensor if it's not submersed.

Yes, I have checked the accuracy of the STC temp probe with my thermometer before and yes, I will be buying a submersible probe tonight. Life's too short to gamble with pilsners.
Why don't you draw out some wort/beer to test?

There's always a chance that your wort is fermenting and creating heat, but your new fridge is struggling to chill it enough (you did mention its on a lot).

Mind you, I've noticed a 1-degree difference in probe outside or inside, but mine is on a stainless fermenter, which is a better conductor of temperature.
 
Fair call, and the answer is tightarseness. Considering I just coughed up $40 in thin metal tubes I'll draw off a 30 cent sample and measure that.
 
TheWiggman said:
Revelation: taping to the side of a fermeter doesn't do a great job for me. ACTUAL REAL-LIFE PIC OF FERMENTER SHOWN BELOW -

attachicon.gif
IMG_3227.JPG

I scored this fridge last week which has an internal circulation fan - perfect (found on the side of the road, the owner said "it's no good, it freezes things all the time and we couldn't fix the temp adjuster thing". Whimmy-wham!).
  • I set my STC-1000 to 10°C for my pilsner. Yeast nutrient, 02 for 1 min. Noted activity after 12h.
  • Day 2 - not much action. Check SG which had dropped 3 points. Bumped temp to 11°C
  • Day 3 (yesterday) - just beginning to see krausen.
I've noticed that the 'new' fridge seems to run a lot for a fridge trying to achieve 11°C.
Considering it should be well underway by now I put a glass (which you can see in the pic) next to the fermenter with my thermometer in it. I left it for a few hours and came back to see it sitting at 6°C. As far as I'm concerned the two liquids should be the same because the air is being recirculated. This explains the slow start, and I gave the pilsner a gentle stroke to show my appreciation that even though it was at 6°C, it was still fermenting.

I had my STC-1000 adjust to +1 so in effect it was set to 10°C, but still controlling 4°C lower than set value. To account for this I've adjusted the offset but it goes to show that it's hard to trust the sensor if it's not submersed.

Yes, I have checked the accuracy of the STC temp probe with my thermometer before and yes, I will be buying a submersible probe tonight. Life's too short to gamble with pilsners.
If you are confident about the accuracy of your stc, the temp it is reading insulated to the side of your fermenter is the one you should be taking notice of. It may even read a couple of degrees cooler than what your fermenting beer actually is.

The glass of water doesn't mean much.
 
Fermentation generates heat. The glass of water won't. Fermenter also has more thermal mass than a small glass of water and is insulated by a different material. About the only thing the two have in common is that they are both volumes of liquid inside a container.
 
I've seen a few mentions in the discussion about people putting the probe in the wort under the cling wrap. Anyone had any issues with this?

I am probably going to buy a few SS thermowells, but that won't be until I get around to buying a step drill bit and ball valves to install in my brew rig for a less ghetto recirc. So this would be a good stop gap while I wait if people have had success.
 
paulyman said:
I've seen a few mentions in the discussion about people putting the probe in the wort under the cling wrap. Anyone had any issues with this?

I am probably going to buy a few SS thermowells, but that won't be until I get around to buying a step drill bit and ball valves to install in my brew rig for a less ghetto recirc. So this would be a good stop gap while I wait if people have had success.
Have been putting the probe straight in without issue for years Give it a wash with warm napisan then a quick soak in some starsan and under the glad wrap it goes. After all you want to measure wort temp.
 

Latest posts

Back
Top