How do you correct a hydrometer reading for temperature?

For a 60°F hydrometer, add about 0.05 °Brix per degree above 60°F. At 80°F a reading of 65.8 is really 66.8.

What should a hot hydrometer read for maple syrup?

About 58–59 °Brix at 211°F for syrup that will be 66–67 °Brix once cool. Read it quickly before the cup cools.

Calculator · → 60 °F

Hydrometer temperature correction calculator

Hydrometers read low when syrup is warm. Enter your reading and the syrup's temperature in the test cup to get its true density.

Hydrometer reading

°Brix

Syrup temperature in the test cup

°F

For a hydrometer calibrated at 60°F — the most common maple hydrometer. (Check yours: long-stem contest hydrometers use 68°F.)

Your target density

True density

66.8°Brix

Correction applied

+1.00°Brix

Right on density. Bottle it hot.

Doing a hot test? Straight off the evaporator at about 211°F, a 66.0 °Brix syrup reads 58.0 °Brix. Read it before it cools.

How it works

The math behind it

Most maple hydrometers are calibrated at 60°F. Near room temperature, add about 0.05 °Brix for every degree above 60°F (subtract below). The correction gets steeper as syrup heats up, so this calculator follows the published correction table point by point, up to +8 °Brix at 209°F and hotter.

The hot test: straight off the evaporator at about 211°F, syrup at 66 °Brix reads about 58 °Brix. Most hydrometers' red lines are set for Vermont's 66.9 °Brix, so finishing "to the line" gives you slightly heavier syrup than the national minimum.

FAQ

Common questions

How do you correct a hydrometer reading for temperature?: For a 60°F hydrometer, add about 0.05 °Brix per degree above 60°F. At 80°F a reading of 65.8 is really 66.8.
What should a hot hydrometer read for maple syrup?: About 58–59 °Brix at 211°F for syrup that will be 66–67 °Brix once cool. Read it quickly before the cup cools.

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