Ever tried to calibrate your thermometer by putting it under your tongue?

I just tried it and it looks like my thermometer may be a degree low. Be careful with it, mine is very sharp and could do some damage in there!

jbsg02 said:

I just tried it and it looks like my thermometer may be a degree low. Be careful with it, mine is very sharp and could do some damage in there!

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Body temp is not a reliable source. The 98.6 deg F is an average of human body temp. My SWMBO normally runs about 99.2. I run at 98.4. It's a good ballpark starting point, but not a true "calibration". That takes more scientific methods. But keep in mind, as much as some try to, homebrewing is not an exact science. It is all about the trial and error and finding what works for you. IMHO, if you take it too seroiusly, you will overanalize and endup ruining your beer. Just enjoy the brewday. So what if your mash temp is a few degrees off, its about the experiance.
Remember the mantra.

RDWHAHB
Relax
Don't
Worry
Have
A
Home
Brew.

I typically run a little low unless I'm sick, but I figured it would be a good way to make sure it wasn't running like 5 degrees or more off.

Don't use the thermometer with the red tip.....

Why don't you just put ice in a cup fill it with cold water let it sit for a few minutes then just stick it in... that is 32F or on the high side, get your water to a rolling boil and there is 212F (I have a brewing buddy that does calibrations of... well I might not be able to go there, but this is what he told me to do for mine).

hmmmbeer said:

Why don't you just put ice in a cup fill it with cold water let it sit for a few minutes then just stick it in... that is 32F or on the high side, get your water to a rolling boil and there is 212F (I have a brewing buddy that does calibrations of... well I might not be able to go there, but this is what he told me to do for mine).

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^Second! But yes, I've stuck it under my tongue as well...

hmmmbeer said:

on the high side, get your water to a rolling boil and there is 212F (I have a brewing buddy that does calibrations of... well I might not be able to go there, but this is what he told me to do for mine).

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This does not work to accurately calibrate because water boils at different temperatures based on altitude. It boils at 212* at sea level. If you are anywhere off the coast, it will boil at different temps. My boils never get higher than 209* in the chicago area (according to my thermometers).

You could also get a reliable calibration from your rectum, but it's a real pain in the azz!

TopherM said:

You could also get a reliable calibration from your rectum, but it's a real pain in the azz!

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Hahahahhahahahahhahaha!!!

One could calculate the boiling point of water at a given altitude provided they had the barometric pressure , or just refer to a handy dandy chart, no harm there!

formula2fast said:

This does not work to accurately calibrate because water boils at different temperatures based on altitude. It boils at 212* at sea level. If you are anywhere off the coast, it will boil at different temps. My boils never get higher than 209* in the chicago area (according to my thermometers).

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Having grown up in Chicago, I am pretty sure your thermometers are off. Chicago isn't at that high of an elevation that you should be off by 3 degrees. Maybe you live on top of a big hill?

Below is a calculator that can help - it requires elevation and barometric pressure of your area. Chicago is roughly 600 ft above sea level, and when I just checked the barometric pressure there it was 29.93, resulting in a boiling point of 210.3

http://www.virtualweberbullet.com/boilingpoint.html
.

formula2fast said:

This does not work to accurately calibrate because water boils at different temperatures based on altitude. It boils at 212* at sea level. If you are anywhere off the coast, it will boil at different temps. My boils never get higher than 209* in the chicago area (according to my thermometers).

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I'm sorry, I didn't get very in depth with the calibration of at what altitude your water boils but you are correct. First you should check with a thermometer that you know is right with either temp you are doing and then use the thermometer in question. In my case, I am at sea level so I get 212 for my boil.

Kind of reminds me of the joke: what's the difference between a rectal thermometer and an oral thermometer? The taste!

Yup body temp isn't useful, nor is it even consistent. Women typically run in the low 97s before ovulation, then it typically jumps up to mid 98s for a couple weeks. ALso, body temp changes by time of day.

Like was said above, check at 32F then check at boiling.

Unless you mash at freezing, boiling, or body temps, your thermometer can still be off. The only reliable way is to calibrate with a certified lab thermometer at mash temps.

Denny raises a good point. For important measurements (like mash temp), I use a lab thermometer, which (you'd hope) won't have any calibration curve problems. The same can't be said for digital or dial thermometers. I bought a certified digital unit from www.mcmaster.com, but I still trust the lab thermometer more.

I use my lab thermo to calibrate my brewing thermo.

weirdboy said:

Having grown up in Chicago, I am pretty sure your thermometers are off. Chicago isn't at that high of an elevation that you should be off by 3 degrees. Maybe you live on top of a big hill?

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Yeah, when I lived in Arizona at about 3300 ft. above sea level, my boil was usually about 209 F by my (admittedly not calibrated) thermometer. Just did a brew today in Michigan at an elevation of 968 ft. above sea level and my thermometer read about 212 F. I guess that means that my thermometer runs a bit high, but 209 in Chicago seems like a clue that the thermometer is a bit off. probably not enough to worry about it though.

Yeah, Chicago at it's highest point is a shade under 600 feet. Should be 211.7 degrees to boil. There abouts.

Meatyboy said:

Yeah, Chicago at it's highest point is a shade under 600 feet. Should be 211.7 degrees to boil. There abouts.

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I believe most online calculators and current barometric readings will get you boiling points in chicago closer to 210.3 to 210.8.