Gravity: temp seems high, but would my hydrometer lie?

[SkunkWorks]

If I believe my hydrometer at the correct density my boil is 221.0 degrees, i.e., 9.8 degrees above the boiling point of tap water.

The temp seems high. Should I doubt my $30 hydrometer?

[DRoseum]

Very possible for temp to be that high due to barometric pressure changes. Hydrometer is a better way to ensure you are at the proper density than a thermometer.

[TapTapTap]

It's possible your hydrometer is defective. You should inspect it for damage at the tip and moisture inside. It's also possible that you're not following good procedures. Syrup temperature and a clean hydrometer are extremely important. Check out the Leader instruction manual (https://leaderevaporator.com/content/Syrup-Hydrometer.pdf) or other reference.

ken

[Baka]

Two questions:
Did you calibrate your thermometer in boiling water at the time you boil sap? If you have one that can't be zeroed out in boiling water, maybe you can accomplish the same by recording the temp. As DRoseum mentioned, the actual boiling temp of water can vary day by day.
For the hydrometer, can you buy or get ahold of someone else's syrup to test it in?

[SkunkWorks]

I did check the thermometer in boiling water.

Next step is to acquire a 2nd hydrometer. I don't see any damage, however I have heard of the paper scale moving. Based on the sheeting I'm thinking the hydrometer is fine.

[buckeye gold]

When nothing else seems right trust the hydrometer, if your confident it's good. Most producers have two hydrometers, you should have a backup. Just test the syrup with both and see if they agree. If they don't your original is probably bad.

[SkunkWorks]

Sounds like a plot by the hydrometer cartel.

[DrTimPerkins]

Next step is to acquire a 2nd hydrometer.

Get a Vermont certified hydrometer also. The state checks each one before it is stamped. They've had entire lots rejected (and thus destroyed) and having several percent of hydrometers in a batch get rejected is not at all uncommon. Have two and swap back and forth between them (and compare them to make sure they read the same). Have them checked annually if possible (often the State Ag Dept or State Maple Association does this at their meetings). Keep an eye out for shifting paper, very fine cracks, or build-up of niter, all of which will throw off the calibration.

[snakes14009]

My hydrometer has a thin connection line to the top of the tube, to tell if the scale has moved. maybe look for on of similar construction and compare the two.