Sap to syrup ratio chart
| Sap sugar | Rule of 86 | UVM · 66.0 | UVM · 66.9 | Syrup / 100 gal sap |
|---|---|---|---|---|
| 1.0% | 86.0 : 1 | 86.8 : 1 | 87.9 : 1 | 1.15 gal |
| 1.5% | 57.3 : 1 | 57.7 : 1 | 58.5 : 1 | 1.73 gal |
| 2.0%typical sugar maple | 43.0 : 1 | 43.2 : 1 | 43.8 : 1 | 2.31 gal |
| 2.5% | 34.4 : 1 | 34.5 : 1 | 35.0 : 1 | 2.90 gal |
| 3.0% | 28.7 : 1 | 28.7 : 1 | 29.1 : 1 | 3.48 gal |
| 3.5% | 24.6 : 1 | 24.6 : 1 | 24.9 : 1 | 4.07 gal |
| 4.0% | 21.5 : 1 | 21.5 : 1 | 21.7 : 1 | 4.66 gal |
| 4.5% | 19.1 : 1 | 19.0 : 1 | 19.3 : 1 | 5.25 gal |
| 5.0% | 17.2 : 1 | 17.1 : 1 | 17.3 : 1 | 5.85 gal |
UVM columns are the revised formula for finished syrup at 66.0 °Brix (the US and Canadian minimum) and 66.9 °Brix (the Vermont and New Hampshire standard, which takes a little more sap). The last column uses the 66.0 formula.
By tree
Sap to syrup ratio by species
| Tree | Typical sap sugar | Sap : syrup |
|---|---|---|
| Sugar maple | 2–2.5% | 35–43 : 1 |
| Red maple | 1.5–2% | 43–58 : 1 |
| Black maple | 2–2.5% | 35–43 : 1 |
| Norway maple | 2.2–2.8% | 31–39 : 1 |
| Boxelder | 2.2–2.8% | 31–39 : 1 |
| Paper birch | 0.5–1.5% | 110–175 : 1* |
| Black walnut | 2–3.5% | 25–43 : 1 |
* Birch is the published figure, not the maple formula: birch syrup takes about 110–175 gallons of sap per gallon. Silver maple is left out because its sugar swings too widely to give one range.
How to read it
Measure the sugar, then read across
Sap sugar is measured in degrees Brix, which is the same as percent sugar. A sap refractometer or sap hydrometer reads it in seconds, and it's worth doing: the ratio can swing from 30 : 1 to well over 60 : 1 between trees and through the season.
The Rule of 86 (86 ÷ sugar %) dates to 1946 and assumed syrup at 65.5 °Brix. The University of Vermont's Proctor Maple Research Center revised it in 2013 to 87.1 ÷ sugar − 0.32 for 66.0 °Brix syrup and 88.2 ÷ sugar − 0.32 for 66.9 °Brix. At normal sap sugar the two agree within a gallon or two.
Planning a season? Pair this chart with the yield estimator for sap per tap, and with finishing temperature for the end of the boil.
FAQ
Common questions
- How many gallons of sap does it take to make a gallon of maple syrup?
- About 43 gallons of 2% sugar-maple sap by the Rule of 86 (86 ÷ 2). The revised UVM formula puts it at about 43.2 for 66.0 °Brix syrup. Sweeter sap takes less: roughly 29 gallons at 3% and 21 at 4%.
- What is the Rule of 86?
- A 1946 rule of thumb (the Jones Rule): divide 86 by your sap's sugar percentage to get gallons of sap per gallon of syrup. It assumed 65.5 °Brix syrup, a little thinner than today's standard, so UVM revised it in 2013 to 87.1 ÷ sugar − 0.32 for 66.0 °Brix syrup.
- Does the ratio change if I measure in litres?
- No. It's a volume ratio, so 43 : 1 means 43 litres of sap per litre of syrup just as it means 43 gallons per gallon.
- Why do I make less syrup than the chart says?
- Real batches leave a little syrup in pans and filters, so the bottled amount usually comes out a bit under the math. Above about 8 °Brix, as with reverse-osmosis concentrate, both formulas also get less accurate.
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