Regulating Termometer

[steve J]

Last year I could not seem to get my termometer that screws into side of the pan near draw off regulated. I have normally boiled water on stove and set it via that . Last year it was wrong from the get go and I tried to adjust it during season while still on the pan with no luck. any fool proof ways of doing it?

[happy thoughts]

You're going to have to recalibrate each time you boil as boiling point can change with barometric pressure. It can vary by a degree or two either way depending on the pressure. A boiling water test is easiest. You can also calculate it from a barometer reading but you still need to know where the boiling point reads on your thermometer to use as your starting point. Many thermometers, especially the standard metal "stick" kind with a round dial can be very inaccurate. Depending on the type of thermometer you have, you might be able to reset the scale via a small screw somewhere but you still need to recheck the boiling point each time you boil.

[eustis22]

"especially the standard metal "stick" kind with a round dial can be very inaccurate"

wait....what? so what are we supposed to use? Digital?

[happy thoughts]

"especially the standard metal "stick" kind with a round dial can be very inaccurate"

wait....what? so what are we supposed to use? Digital?

You'd probably be better off with a digital of the type made for ovens though any thermometer can be inaccurate. Here's a really good webpage about the differences in thermometers. It's geared to BBQ grilling but it contains a lot of general info about all types of food thermometers out there. Look for the section on bi-metal dial thermometers. You won't be happy:( In one place a famous cook calls them "as accurate as a sniper scope on a nerf gun".

http://amazingribs.com/BBQ_buyers_guide/thermometer_buying_guide.html

[Flat Rock Farmers]

Hey Guys, when I was taught to boil I was told to use the thermometer as a guideline as to when it was just about syrup. If it was within a point or so we'd draw off a bit and do a hydrometer test.
Sometimes it would be syrup when the thermometer read 7 or once in a while it would be syrup at 6 or 8 and we'd draw off accordingly. I believe my mentor only calibrated his thermometer once
at the beginning of the season. Would this be wrong to keep doing?

[happy thoughts]

using temp as a guideline would be the way to go but you really should check for accuracy at least once a year AND calculate for barometric pressure EACH time you boil because boiling point WILL fluctuate because of air pressure. Today's 212.5 boiling point might be tomorrows 210.9 boiling point and the density of your syrup will depend on that.

Here's another review of cooking thermometers. You'll notice almost all of them are digital and one of the 2 stick dial thermometers tested did not test accurate. I have tried all types of thermometers for syrup making short of the very accurate but generally more expensive thermocouple (instant read) type. The one I now use, have found to be accurate, and like best is the taylor digital (#3 in the above review). About $20 at target and it has lasted several years for me. I don't have an evaporator so don't know how well this would work in one but I would definitely want to test any of the metal dial thermometers for accuracy in a boiling water test at least once each year. Just my 2 cents :)

http://www.goodhousekeeping.com/product-reviews/cooking-tools/food-thermometer-reviews/food-thermometer#slide-1

[lafite]

I calibrate at the beginning of the season. I'm only 200ft above sea level so the fluctuations aren't as drastic. I use my finishing pan before going into the press to get a precise reading with the hydrometer. so far this year I've only had to finish for 10-15 minutes max!

[happy thoughts]

altitude definitely affects boiling point but so does barometric pressure and that will change constantly no matter what your altitude. The difference can be significant.

try this calculator and play with the pressure change for the same altitude...

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

[steve J]

Well the first year I calibrated it once and it kept me in the ball parl all season. I always finish syrup on a turkey fire burner in 2 gallon batches I have small rig. But I could not even get in the ball park with this thermometer last year. Also I do understand you should calibrate each time but how do you do that when you leave your pan full of partially boiled syrup. If you unscrew the thermometer your going to leak syrup?

[happy thoughts]

Also I do understand you should calibrate each time but how do you do that when you leave your pan full of partially boiled syrup. If you unscrew the thermometer your going to leak syrup?

Let me clarify- test the thermometer at the beginning of the season in boiling water. That should give you a baseline of how the thermometer reads. You should do the calculation for the boiling point of water at the pressure reading at the time you test it. So if you know the boiling point should read 211 at the time you tested it and it reads 212 then you know your thermometer is a degree off to begin with. If you can adjust it, do so. If not use 211 as your baseline so you know that at 218 (+7F) you should start looking for syrup.

If you have one of those bi metal thermometers as I suspect you might, their accuracy is subject to rough handling. If you don't hit it or shake it you shouldn't have to find a baseline reading again. After that you should only need to do the math for the air pressure at the time of boiling with that baseline +/- accuracy you determined for your thermometer at the beginning.. You shouldn't need to remove the thermometer from the evaporator.

Next year I'd recheck in the same way again.

Hope that's clearer than mud :)

[wiam]

Hey Guys, when I was taught to boil I was told to use the thermometer as a guideline as to when it was just about syrup. If it was within a point or so we'd draw off a bit and do a hydrometer test.
Sometimes it would be syrup when the thermometer read 7 or once in a while it would be syrup at 6 or 8 and we'd draw off accordingly. I believe my mentor only calibrated his thermometer once
at the beginning of the season. Would this be wrong to keep doing?
You do not need to "calibrate" your thermometer on your evaporator daily. I have been sugaring for 30 years and have never boiled water to set mine. It is just a reference. Hydrometer is the boss. When the hydrometer says syrup look at thermometer. Draw off close to there. Do not make this so complicated

[bowhunter]

Cool. Thanks for the link.

[happy thoughts]

You do not need to "calibrate" your thermometer on your evaporator daily. I have been sugaring for 30 years and have never boiled water to set mine. It is just a reference. Hydrometer is the boss. When the hydrometer says syrup look at thermometer. Draw off close to there. Do not make this so complicated

You're right wiam. The hydrometer is boss so let's just keep it simple about thermometers. First don't assume any thermometer is anywhere near accurate. It's is good to have a baseline though to get a feel for it's accuracy, If you see differences in temp for "doneness" from day to day as the OP did then that's normal and more likely due to variations in air pressure all other things being equal.

[Flat Rock Farmers]

Thanks Wiam. That's the answer I was looking for! I usually calibrate mine the day of our first boil in boiling water and go the rest of the season from that.
Keeping it simple is the way to go!