Calibrating at close to the temperature you are going to use the equipment is a really good idea. If you have a reasonably good glass thermometer it should be fairly consistent across its range, ideally a two point calibration is best, that is to say if it's good at both 0 and 100, you can expect it to be reasonably good in between. As mentioned above water as a standard can be slightly less accurate than other methods, unless you make sure you have used pure water and allowed for altitude and all that.
I find the Naphthalene melting point method very effective, and it isn't affected by altitude
MHB
Bandito
Sure someone might be "allergic" to Naphthalene this method wouldn't be the best one for them - I've had a look at the exposure recommendations and wouldn't be too worried. No doubt there are a bunch of other chemicals one could use.
M
Sinkas
One very talented brewer was close to quitting brewing, attenuation missing by 5-10 points and efficiency all over the place, others consistently not getting the results they were looking for, either too dry or sweet.
As to which way readings were out - therein lays the rub, it's not uncommon these days for brewers to have 2-4 different sensors involved in the brew cycle, if they aren't calibrated there is no way to tell if they are going to be reading over or under. True a couple of degrees in mash temperature might not make that big a difference, especially if it's consistent, you can adjust your settings to suit.
If your HTL controller was reading a couple of degrees under and the dial thermometer in your mash tun was a couple of degrees the other way well you try doing a strike water calculation, it's no fun.
A couple of degrees on each can add up pretty fast to an unacceptable amount of error, especially if you consider how easy and inexpensive it is check that at a minimum all your equipment is reading consistently.
M
I find the Naphthalene melting point method very effective, and it isn't affected by altitude
MHB
Bandito
Sure someone might be "allergic" to Naphthalene this method wouldn't be the best one for them - I've had a look at the exposure recommendations and wouldn't be too worried. No doubt there are a bunch of other chemicals one could use.
M
Sinkas
One very talented brewer was close to quitting brewing, attenuation missing by 5-10 points and efficiency all over the place, others consistently not getting the results they were looking for, either too dry or sweet.
As to which way readings were out - therein lays the rub, it's not uncommon these days for brewers to have 2-4 different sensors involved in the brew cycle, if they aren't calibrated there is no way to tell if they are going to be reading over or under. True a couple of degrees in mash temperature might not make that big a difference, especially if it's consistent, you can adjust your settings to suit.
If your HTL controller was reading a couple of degrees under and the dial thermometer in your mash tun was a couple of degrees the other way well you try doing a strike water calculation, it's no fun.
A couple of degrees on each can add up pretty fast to an unacceptable amount of error, especially if you consider how easy and inexpensive it is check that at a minimum all your equipment is reading consistently.
M
