Quote of the Day
Statistics are like brief swimming costumes; what they reveal is interesting, but what they conceal is absolutely vital.
— old statistics professor
I am being a good citizen and socially distancing myself by staying at my cabin in northern Minnesota – avoiding people is easy in the dense forest that surrounds my residence. When I went out for my daily walk today, I saw that my neighbor had put out maple sap bags (Figure 1). Most folks around here collect their sap in these blue bags.
Some of my fondest boyhood memories are of my father driving the tractor that was pulling a trailer on which my grandfather and I sat on while going from tree to tree gathering pails of maple sap.
My brother has also been collecting sap this spring and he is reporting that it is taking 30 gallons of sap to obtain one gallon of syrup, which is better than the 40-to-1 ratio that he usually reports. This means the sap is a bit sweeter this year than last. Maple syrup typically has a sugar content greater than 66%, but maple sap typically has a sugar content of about 2.5% but can vary anywhere from 1% to 5%.
You can estimate the amount of sap you will need to make a gallon of maple syrup using the Jones Rule, or Rule of 86 (Equation 1). As an example of using the Rule of 86, given a 2.5% sugar concentration sap, you will need 86/2.5 = 34 gallons of sap to make 1 gallon of maple syrup.
- NSap is the number of gallons of maple sap per gallon of syrup.
- CSap is the sugar concentration of maple sap expressed in percent.