Author Topic: Calibrate those thermometers!  (Read 967 times)

Offline denny

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Calibrate those thermometers!
« on: May 17, 2016, 06:47:29 PM »
My last few batches have had a low conversion efficiency compared to normal, and the wort runoff has been kinda cloudy.  My brewhouse efficiency has also been a bit low.  But on all of those brews, I've been doing multiple things at once and hadn't taken the time to look for an answer.  Today, doing the first of 2 test brews, I figured I'd check calibration on things.  Turns out my brewing thermo read 15F lower than my calibration thermo!  Recalibrated the brewing thermo and I'm back up to 97% conversion efficiency and the mash runoff was crystal clear, like it should be.  DOH!
Life begins at 60.....1.060, that is!

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Offline yso191

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Re: Calibrate those thermometers!
« Reply #1 on: May 17, 2016, 06:49:24 PM »
Denny, what do you use for a calibration thermometer?
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Offline kramerog

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Re: Calibrate those thermometers!
« Reply #2 on: May 17, 2016, 06:52:00 PM »
Denny, any idea what caused your brewing thermometer to get out of whack?  What kind of thermometer?

Offline denny

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Re: Calibrate those thermometers!
« Reply #3 on: May 17, 2016, 06:55:47 PM »
Denny, what do you use for a calibration thermometer?

I have both an alcohol immersion thermo and a VWR NIST certified "lollipop".  I used the lollipop today, but if I want to be dead accurate I break out the immersion.
Life begins at 60.....1.060, that is!

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Offline denny

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Re: Calibrate those thermometers!
« Reply #4 on: May 17, 2016, 06:58:26 PM »
Denny, any idea what caused your brewing thermometer to get out of whack?  What kind of thermometer?

It's a bimetal dial thermo that I've had since I started brewing 18+ years ago.  Came with my original equipment.  Since it's made to be adjusted, sometimes the adjustment slips.  But I also dropped it a while back and hadn't checked it since then  Normally I check it every few brews, but things have been so crazy the last few times I brewed I hadn't gotten to it.  Another lesson...if yer gonna brew, then BREW!  Don't try to write a book and answer email at the same time!
Life begins at 60.....1.060, that is!

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"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts." - Bertrand Russell

Offline kramerog

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Re: Calibrate those thermometers!
« Reply #5 on: May 17, 2016, 07:04:31 PM »
Denny, any idea what caused your brewing thermometer to get out of whack?  What kind of thermometer?

It's a bimetal dial thermo that I've had since I started brewing 18+ years ago.  Came with my original equipment.  Since it's made to be adjusted, sometimes the adjustment slips.  But I also dropped it a while back and hadn't checked it since then  Normally I check it every few brews, but things have been so crazy the last few times I brewed I hadn't gotten to it.  Another lesson...if yer gonna brew, then BREW!  Don't try to write a book and answer email at the same time!

Thanks.

Offline rob_f

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Re: Calibrate those thermometers!
« Reply #6 on: May 18, 2016, 12:38:40 PM »
I had the same thing happen on my HLT thermometer. I had been doing cold sparges before Marshall made it cool. It was 50 degrees off. I keep it out in the garage and I think the temperature swings over 15 years messed with it. I calibrated it to my Thermopen.

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Offline brewinhard

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Re: Calibrate those thermometers!
« Reply #7 on: May 18, 2016, 11:05:03 PM »
Denny, any idea what caused your brewing thermometer to get out of whack?  What kind of thermometer?

It's a bimetal dial thermo that I've had since I started brewing 18+ years ago.  Came with my original equipment.  Since it's made to be adjusted, sometimes the adjustment slips.  But I also dropped it a while back and hadn't checked it since then  Normally I check it every few brews, but things have been so crazy the last few times I brewed I hadn't gotten to it.  Another lesson...if yer gonna brew, then BREW!  Don't try to write a book and answer email at the same time!

I don't like those dial-face thermometers.  I use to use one when I first started brewing and would always be a few degrees off every few brews. It seemed like even the slightest bump of it would mess up the calibration. Ever since I bought a Thermapen, I have been completely pleased with the purchase in both speed and accuracy. Also good to have one to calibrate other thermometers to as well.