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Suggestions for a good thermometer for calibration

I am slowly making improvements in my processes and I think that my next step needs to be to address my thermometers and their accuracy. While I dont have any evidence that my thermometers are not accurate, I need to be sure that they are in order to make the next step. I currently use 2 or 3 different thermometers in my brew day. 2 of them are the old needle on a dial type and 1 is a digital food thermometer that I use when I am cooking. Does anyone have a suggestion for a good, fairly inexpensive calibration thermometer that I can use to make sure that my current thermometers are reading accurately in “beer brewing” range?

I’m sure you have looked for one already since you are asking for an inexpensive suggestion. It is one of those “you get what you pay for” items and then you may need to have it calibrated ($$) from time to time.

I’ll ask the obvious. Have you checked all three simultaneously to see each one’s variability? Checking at 32F and 212F is not difficult but getting a handle on how each one reads somewhere in between is the question.
I did the following with a couple I had. Brought a small pot of water boiling and placed all therms in water (probes not touching pot), noted the temp at full boil. Kept therms in pot and turned off the heat, every few minutes noted the temps of each. Kept doing that until I hit a little below temp of what I usually pitch at. I also had a digital therm that was in there to monitor as well.

In my case I chose the one I felt was the more accurate and went with it. From batch to batch it was all relative. Sounds like you have need for more accuracy.

Didn’t answer your direct question about “inexpensive calibration thermometer” because I don’t think an inexpensive cal thermoter exists.

Good Luck,
Brew On

Keep in mind that barometric pressure and elevation affect your boiling point.

exactly, my water boils at 209* my elevation is about 2800 ft ... er-61.aspx

This is the one I use. It’s waterproof, cheap, and NIST Traceable. The only downside is slow response time, but if you’re only using it for calibrations that wouldn’t be a problem.

I think I am around 4000ft. is there a boiling chart somewhere for this? sorry not trying to hi-jack the thread just got me thinking. ... _1344.html

At 4000 ft you’d boil at about 204°F.

Awesome! Thanks! would this effect my strike and mash temps then if callibrated to 32F or should I just not over think this? Thanks again! ... er-61.aspx

That is a great price for one that comes with a certificate. When you say it has a slow response time are you talking longer than 10 seconds?

The freezing point (32°F) doesn’t really change with atmospheric pressure. But the point of calibrating against a known-good thermometer is that one of your other thermometers could be accurate at freezing, or boiling, or both, but not at mash temps. You really need to check it at ~160°F to be sure.

Probably 10-20 seconds, depending on the temperature you’re measuring. About the same as any cheap digital IME.

All of the thermometers I currently use are pretty accurate at boiling and freezing points. I just want the ability to check their accuracy in the 140 to 170 range and be able to adjust so that I know I am being as accurate as possible. I haven’t looked around much yet but I recall seeing a thread a while back about thermometers but a search using the search function on the forum here didnt turn up what I was looking for so I thought I would ask. I dont want to spend $100 bucks on a thermometer but if I could find something reliable that I can use to adjust my other tools somewhere in the $30 range I would find that acceptable.

Brewing today with the benefit of my new calibrated thermometer from Arbor Scientific as suggested by a10t2. So far it seems that my current thermometers are not that far off. My main one was about 4 to 5 degrees off in the 70 to 90 degree range and about 2 degrees off in the 140 to 160 range but above that its almost dead on. I think knowing that now means that I have been mashing a little higher than I expected in the past and I can now make that adjustment going forward.

Thanks for all of the suggestions and comments.

I do not want to steal the OP’s thread, but it does look like he has gotten what he wanted out of it. I enjoyed reading it. In fact, so much so that I just posted on my local home brewing club the idea that as a club we should purchase a good thermometer that members could check out to calibrate their own thermometers.

As a10t2 suggested the thermometer he recommended does take a few seconds to get to an accurate reading but if you are just using for calibration then that isnt much of a concern for me. All in all it does exactly what I need it to do and if it helps me improve my overall product then that is what it is all about.

In following the topic I had found an inexpensive tool for checking three points 32f & 130f which gets closer to 140-170 and then I check 212f on the stove, (well 210f in my case as I am at 1000ft above sea level.) ... lbath.html

And I use as advertised with a NIST traceable calibration thermometer.
As an aside I paid quite a bit for mine, But I like the link to the above thermo for $25 bucks good reference for the future!

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