Trust the thermometer or hydrometer?

[Goggleeye]

I can guess what most of you are thinking-go with the hydrometer. I have three different hydrometers, all of which read the same. But when I go to density according to hydrometer, our syrup is so thick it will hardly filter and some of our customers even complain how thick it is. So we’ve bottled by temp now for several years. When we compare ours to commercial maple, it matches when we go by temp. The stuff we go by hydrometer is corn syrup thick. I know I’m getting the temps right when using the hydrometer. I’m a bit of a perfectionist when it comes to my syrup, and it bugs me scientifically that my thermometer and hydrometer readings don’t match. Any thoughts? Btw, when the hydrometer is on, the temp reads 222, and we are about 350 ft above sea level.

[OGDENS SUGAR BUSH]

temp should be 211f when you use the hydrometer

[bill m]

You say your 3 hydrometers all read the same but have they been checked to be sure they are calibrated correctly? Also 222 degrees sounds way to high.

[upsmapleman]

Sounds like you are using the cold line with hot syrup. Check your syrup when it is 60 degrees and see what it reads.

[Goggleeye]

The syrup is boiling at 222, I’m checking density once it cools to 211. And I’m using the hot line. I will give it a try at 60 with the next jar I open.
No, haven’t had the hydrometers checked. How would I do that?

[Russell Lampron]

You need both to be accurate but the hydrometer is what you trust. If you can't find someone near you to test your hydrometers buy a new Leader hydrometer. They are VT certified and there is a red line in the top of the glass that ends at the top line on the paper. If the paper slips from banging it off the bottom of the hydrometer cup you know right away. That 222* temperature is about 3* higher than syrup should be so it's still too heavy.

[Chickenman]

Sounds like your thermometer is out of calibration. I agree with having your hydrometer checked, but you say the 3 are agreeing with each other, I would trust them. Go with the hydro reading.

[buckeye gold]

I may be wrong on this and if I am someone please correct me. A simple way to check relative accuracy is to prepare a test solution. The simplest and most relative would be a sugar solution. Use distilled water or permeate and make a 66% sugar solution. I'll use a simple example:

bring 210 grams of distilled water to a boil remove from heat, it can cool slightly
Have 132 grams of sugar already weighed out and setting on a scale in a heat capable container (don't forget to tare off the container)
add the hot water until the scale reads 200 grams and mix until sugar is completely in solution.
Check weight after cooling and add water to bring to 200 again in case enough evaporated to change solution (it probably won't)
Then test your hydrometers at 60 with this solution, they should read 66 brix. I wouldn't be too concerned if they were slightly off (.1 -.2 brix) as this isn't a lab grade solution, but they should be really close. This should give you an idea if they are way off or not.

A known glycerin solution would be best, but this uses simple household items. You can use the syrup water for sweetener

[DrTimPerkins]

What are you using for a thermometer? Did the calibration screw get changed? What is the temperature of boiling water?

https://www.youtube.com/watch?v=Icn3Fgongjo

[maple flats]

I used to, after checking the boiling point of water that day, adjust the zero of the thermometer but at times the density seemed off a little. I then got a Marcland baro/boil temp meter. That helped a lot since by then I had an auto draw. I now check that meter every 2 hours or so, and reset the auto draw if needed. Before that I had only tested the boiling temp to start the day, but the barometric pressure changes often, and with every such change the boiling point of water changes. This might also be part of the issue. I now get very close, but I final check everything using one of my hydrometers. I now use a Smoky Lake Gold hydrometer, it is only better because it has a ref line to indicate if the paper has not moved. When you buy a hydrometer you can make such a mark in the box it came in for future reference. I just never did that in the past.