Tap, tap, tap, followed by clink, clink, clink are the sounds of the beginning of another maple syrup season. All of the students had the opportunity to tap sugar maple trees this week during the Outdoor Skills classes. Students identified maple trees large enough to tap, determined a good place to drill, drilled a hole about 2 ½” deep, cleaned wood shavings out of the hole, tapped in a spile, hung a bucket on the spile’s hook, and put a lid on the bucket.
The students will also have the “opportunity” to continue to collect sap after school during the season. With 5-gallon pails in hand groups of students will visit about 150 trees collecting sap.
A good sap flow day is when nighttime temperatures dip below freezing, low 20’s is enough of a dip and followed by day time temperatures rise above freezing. So, what is going on? According to Cornell University, sap flow is a result of pressure changes in the tree's xylem. In the winter when the maples freeze, gasses are pushed from the xylem into surrounding tissues creating negative pressure, compared to atmospheric pressure. In spring when temperatures rise above freezing the gases expand and dissolve back into the sap which creates positive pressure. When a maple tree is tapped, the pressure inside the tree is greater than the pressure outside the tree, which cause the sap to flow.
The sap will be boiled in Conserve School’s evaporator until it is nearly syrup and then finished on a gas stove. The average sugar content of sap is about 2%. It takes about 43 gallons of 2% sap to make 1 gallon of maple syrup. Sap becomes syrup by boiling until the temperature of the liquid is 7 degrees above the boiling point of water. All maple syrup whether it is light or dark is 66.5% sugar. The finished syrup is 66.5 percent sugar and 33.5 % water. The syrup made this season will be served to Conserve Students of CS 18 and CS19. Wild Rice in the fall and Maple Syrup in the spring are the two native Northwoods foods students enjoy during their stay at Conserve School.