Tapping Maple Trees

The history, the science and today's art of making pure maple syrup

Feb 21, 2009

The tradition of making pure maple syrup has not died. Learn how Native Americans discovered this natural sweetener and how syrup producers today carry on the tradition.

The days are sunny and getting warmer, about 47 degrees, and at night the temperature drops just below freezing. Spring is on its way, but right now it’s the perfect time for maple sugaring.

Maple sugaring is the time-honored tradition of tapping sugar maple trees for sap to make pure maple syrup. The process of making maple sugar dates back as far as 1609 with the Native Americans.

History of Maple Sugaring

Though there are many legends of how Native Americans discovered maple sugar, they most likely discovered the sweet taste of sugar maple sap by eating “sapsicles,” the icicles of frozen maple sap that form on the end of a broken twig.

During the short four to six-week sap harvesting season, Native Americans would set up camp in a sugar bush, an old stand of maple trees. Finding trees that were old enough to be tapped, usually 40 years old or 10 inches in diameter, Native Americans would make a v-shaped slash in the tree trunk and collect the sap in a birch bark container called a mokuk.

Because they didn’t have metal pots to boil the sap, Native Americans would drop hot stones into the mokuks to boil away the water from the sap. Sap is about 97 percent water and 3 percent sugar when it comes out of the tree and it takes about 40 gallons of sap to produce one gallon of syrup. Though 10 gallons seems like a lot, this is only a small portion of the trees’ total sap production and will not hurt the tree.

The Science Behind it All

Every tree needs air, water, sunlight and soil to live. These vital resources combined with carbon dioxide and chlorophyll allow trees and other green plants to make their own food through photosynthesis. The food produced is called sap.

In late February and early March when the days begin to reach temperatures between 40 and 50 degrees and the nights are still freezing, the sap begins to rise from the tree’s roots to feed the new leaf buds. As night falls, the sap returns to the roots so it will not freeze.

The rise and fall of the sap is completely dependent on the weather. If the temperatures are too cold, the sap flow will stop so it does not freeze. If the temperatures are warm and stay warm, the sap flow will stop. It’s pertinent that the temperatures alternate between cold and warm because at night when it is cold the tree will cool down and absorb moisture from the ground via the roots and then when it’s warm during the day the tree warms up, the internal pressure builds and the sap will run from a taphole or even a broken twig.

Producing Maple Syrup Today

Because it takes about 40 gallons of raw sap to make one gallon of pure maple syrup, today’s collection process has greatly advanced since the Native Americans. Now, sugar makers use drills to tap the trees and metal spouts and buckets to collect the sap. Though boiling the sap still takes time, today there are sugarhouses that are equipped with pipelines and evaporators.

The design of evaporators has not changed much over the years. The evaporators are used to boil the sap into syrup and are made up of flat pans that sit on an arched firebox. Inside the firebox, wood, oil, gas and/or coal are burned at the front end and the flames are drawn along the underside of the pan. This will heat and boil the sap. Depending on the number of trees the sugar maker has tapped, an evaporator can range from two feet wide and six feet long up to six feet wide and 20 feet long.

This setup would be used in commercial production. Many people who make maple syrup as a hobby or on a smaller scale boil down their sap on the kitchen stove.

The copyright of the article Tapping Maple Trees in Ethnobotany is owned by Julia Bourque. Permission to republish Tapping Maple Trees in print or online must be granted by the author in writing.