I recently tested my dial thermometer for accuracy and it was way off (by 10 degrees at both freezing and boiling – who knows how much in the middle of the range!). Luckily, my digital traceable thermometer, which I use to measure mash temp, was dead on. Anyway, I’m looking to replace my dial thermometer with another stick-style thermometer that I can clip on to my HLT, which is a 5 gallon SS kettle.
I would also be open to a brewmometer, so long as I can count on it to be accurate. Does anyone have any recommendations?
I really like dial thermometers for their durability, but they do have to be checked regularly. I think you would be better off getting a NIST-traceable mercury thermometer and only using it to calibrate your working thermometers. The working thermometers need to be calibrated in the typical mashing temperature range, not freezing and boiling. That is what I do.
Most dial thermometers are adjustable. If its off by 10 at both ends of the scale it is probably accurate, just the pointer is not aligned properly with the numbers. Look and see if there is a hex nut between the stem and the dial. if so, take a wrench** and hold the nut and twist the dial face until it reads what you expect then retest.
It is much easiter to calibrate while holding the stem in a glass of water/ice than over a pot of boiling water. Besides, boil temp varies with altitude where the ice/water doesn’t.
** I have found a left-handed-metric adjustable wrench works best. :
Believe me, I’ve got my eye on it! But I just can’t part with $100 for a thermometer right now.
tubercle, when I tested my dial thermometer, it read 10 degrees high at freezing. I adjusted the hex nut so it read 32. I then tested it at boiling temp and it read 10 degrees low. :-\ I ordered one of MoreBeer’s higher quality dial thermometers today.
I use a cheapo dial thermo I found at safeway for 6 bucks or whatever. I do teh ice water boiling water thing before each brew session and it seems to work okay. I wish the dial were bigger and the probe longer but hey it works. I suspect I got really lucky but I am not looking that particular horse in the mouth.
I like the idea of the Thermapen and I like that its calibrated. It does seem like it could be a good everyday tool. It is expensive though.
This still doesn’t alleviate the problems inherent with any electrical or mechanical device…they can go out of calibration. That’s why I like the security of that old fashion mercury in glass thermometer for calibration checking. The only way its going to go out of calibration is for it to be broken and then you have a whole lot more problems. My NIST thermometer only comes out for calibration and is never used for real work. Of course, that old fashion thermometer has to be calibrated to an NIST standard for it to be worth anything.
I took a look at some NIST mercury thermometers and they were really expensive (around $200). Are you aware of a source for more a more affordable one?
Ebay is always the resource for stuff that is too expensive at the retail level. I found one after a couple months of watching for about $40. Still expensive. The other option that clubs should consider is to buy a communal reference thermometer that is brought to club meetings occassionally so that members can check their instruments at the mashing temp range. I find that checking calibration once or twice a year is quite sufficient unless an instrument is abused.
