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

  1. #1
    Join Date
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    Default Gravity: temp seems high, but would my hydrometer lie?

    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?

  2. #2
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    Murrysville, Pennsylvania
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    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.
    D. Roseum
    www.roseummaple.com
    ~100 taps on 3/16 custom temp controlled vacuum; shurflo vacuum #2; custom nat gas evap with auto-drawoff and tank level gas shut-off controller; homemade RO #1; homemade RO #2; SL SS filter press
    2021: 27.1 gallons
    2022: 35 gallons

  3. #3
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    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...Hydrometer.pdf) or other reference.

    ken
    Ken & Sherry
    Williston, VT
    16x34 Sugarhouse
    1,500 taps on high vacuum, Electric Releaser & CDL Sap Lifter
    Wood-Fired Leader 30"x10' Vortex Arch & Max Raised Flue with Rev Syrup Pan & CDL1200 RO
    https://www.facebook.com/pumpkinhillmaple/

  4. #4
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    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?

  5. #5
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    Hartford
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    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.

  6. #6
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    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.
    125-150 taps
    Smokey Lakes Full pint Hybrid pan
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    Southern Ohio

  7. #7
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    Hartford
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    Sounds like a plot by the hydrometer cartel.

  8. #8
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    Quote Originally Posted by SkunkWorks View Post
    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.
    Last edited by DrTimPerkins; 02-21-2022 at 07:19 AM.
    Dr. Tim Perkins
    UVM Proctor Maple Research Ctr
    http://www.uvm.edu/~pmrc
    https://mapleresearch.org
    Timothy.Perkins@uvm.edu

  9. #9
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    ny
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    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.

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