Maple Syrup Grade Calculator
USDA maple grade from light transmission %Tc.
What it does
Maple grades read light, not taste buds. Percent transmission at 560 nm sorts syrup into Golden, Amber, Dark, and Very Dark at 75, 50, and 25 %Tc cutoffs, with taste names Delicate through Strong riding along. A 68 %Tc sample grades Amber seven points shy of Golden.
The tool above grades any reading with next-grade gaps attached. Enter %Tc and it prints the USDA Grade A class with taste name plus points to the next grade. Defaults show Amber; 30 %Tc reads Dark 20 points from Amber while 80 reads Golden top grade.
Federal and state rules match exactly. USDA AMS 2015 standards set the four bands with the 10 mm spectrophotometer method against glycerol, and Vermont regulations mirror every cutoff with 66.9-68.9 Brix packing density. Processing Grade catches off-flavor syrup for bulk only.
Grade guides use more than color. Darker grades cook stronger maple flavor into recipes while Golden dresses tables, so grade choice follows the plate. Calibrated graders with matched cells keep readings honest across seasons.
How to use
- Enter %Tc from the grader.
- Read the grade first.
- Read the next-grade gap.
- Pack Grade A at 66.9-68.9 Brix.
- Bulk off-grade as Processing.
- Check state rules yearly.
Formula
- %Tc
- Light transmission percent, 0 to 100.
USDA AMS 2015 standards with 10 mm / 560 nm glycerol method; Vermont mirrors cutoffs exactly.
Worked example
Example: 68 %Tc
Defaults: 68 %Tc.
- Input: 68 %Tc transmission.
- Check: 50.0 <= 68 <= 74.9 is true.
- Grade: U.S. Grade A Amber / Rich.
- Next: 75 minus 68 = 7 points to Golden.
- Tool shows Grade A Amber / Rich, 7 points to Golden.
Reference table
| %Tc | Grade | Taste |
|---|---|---|
| >=75.0 | Golden | Delicate |
| 50.0-74.9 | Amber | Rich |
| 25.0-49.9 | Dark | Robust |
| <25.0 | Very Dark | Strong |
Limits
- Grade math only. Flavor defects separate.
- Calibrated graders assumed.
- Brix packing simplified to band.
- State fees and labels excluded.
Common mistakes
- Eyeballing color instead of grading.
- Mixing Brix with %Tc scales.
- Selling Processing Grade retail.
- Skipping calibration checks.
- Grading hot unfiltered syrup.
Try it yourself
Quick checks. Answers sit tucked under each question.
30 %Tc?
25.0 <= 30 <= 49.9 is true: Grade A Dark / Robust. Next 50 minus 30 = 20 points to Amber.
80 %Tc?
80 >= 75 is true: Grade A Golden / Delicate. Next: top grade.
18.5 %Tc?
18.5 < 25 is true: Grade A Very Dark / Strong. Next: bottom grade.
Questions
How is grade figured?
At/over 75 Golden, 50-74.9 Amber, 25-49.9 Dark, under 25 Very Dark. Here Amber.
What is %Tc?
Percent light transmission vs glycerol at 100 %, 10 mm path, 560 nm.
What are the taste names?
Delicate, Rich, Robust, Strong across Golden, Amber, Dark, Very Dark.
What density packs Grade A?
66.9-68.9 Brix at 60 F for Grade A packs; Processing Grade skips retail.
Can syrup fail Grade A?
Yes. Off flavors and damage drop syrup to Processing Grade for bulk only.
Do states match USDA?
Yes. Vermont mirrors USDA bands with identical cutoffs.