The sap in maple trees is beginning to run, a sure sign that spring is on its way. Called “sugaring-off,” the period of time when the sap is collected can last as long as ten weeks, although much of the sap is collected during the first ten days.

The sugar in the sap nurtures the tree and provides fuel for the spring growing season. Sap from sugar maples has the highest sugar content, so it’s the variety most commonly tapped. A grove of sugar maple trees is called a “sugarbush” and maple syrup producers commonly refer to themselves as “sugarmakers.”

Way back, most of the maple sap was boiled down to make maple sugar. But when inexpensive white sugar became readily available, the market for maple sugar evaporated, and sugarmakers shifted much of the production to maple syrup.

Maple sap is typically 98% water and 2% sugar. “Real” maple syrup, by definition, is never more than 35% water, so the excess liquid has to be boiled off. “Imitation” maple syrup- or pancake syrup- is generally a mix of corn syrup and artificial flavoring.

Native Americans were the first to harvest maple sap. They used a tomahawk to slash the bark and angled the cut so the sap would flow away from the tree, which made it easier to collect.

Boiling off the water would have been difficult, since their containers were typically made of wood and couldn‘t be used over an open fire. If they left the collected sap out in the still frigid night air, some of the water would rise to the top and freeze, and the resulting ice could be easily removed.

The settlers soon realized that slashing the bark to collect the sap was inefficient and potentially harmful to the tree. They drilled tapholes, instead, and used buckets suspended from a metal spike to collect the sap. Still, turning the sap into a usable sweetener was a time-consuming, labor intensive process.

Putting heated stones in the sap to boil off excess water was another possibility, and the two methods may have been used in combination. Even so, the results would have been mediocre at best. As a result, maple sugar and maple syrup weren’t made in quantity until European settlers arrived with their iron pots.

Modern sugarmakers still collect maple sap by tapping the trees. A tree has to have a diameter of at least nine or ten inches at a height of four to five feet before it can be tapped without damaging the tree.

Using a 5/16 or 7/16-inch bit, sugarmakers drill tapholes that are 2 to 2 ½ -inches deep. While large trees can support multiple tapholes, tapping stresses the tree, and the number of taps rarely exceeds three or four.
A spout or “spile” is inserted in every taphole. The sap flows through the spout into either a covered bucket that’s emptied manually or plastic tubing that takes it directly to the sugarhouse for processing.

It takes forty gallons of sap to produce a single gallon of maple syrup or three quarts of maple sugar. Mechanization has made production easier, but boiling out the excess liquid in the sap is still the only way to make maple syrup.

Modern sugarhouses are equipped with storage tanks for the sap, a wood or oil-fired evaporator from boiling the sap, filters, barrels for storing the syrup, and packaging equipment.

Maple syrup is graded by color and flavor, rather than quality. Grade A Medium Amber (No.1 Light in Canada), the most popular grade of table syrup, is darker than the Light Amber produced earlier in the season and also has a more pronounced maple flavor. Grade A Dark Amber, or even a late-season Grade B, is typically used for cooking.

Maple syrup should be kept in glass containers and refrigerated after it’s opened. If it’s bought in quantity, the syrup can be portioned into freezer-safe containers and frozen. Tin containers aren’t recommended for long-term storage.

Locally, the River Trail Nature Center (3120 N. Milwaukee Avenue, 847.824.8360) in Northbrook gives Chicago-area residents an opportunity to experience sugaring-off first hand. Saturdays and Sundays from February 26-March 19, the center will be hosting 45 minute, family-oriented demonstrations at both 10:30 am and 1:30 pm. The culminating program on Sunday, March 20 (11 am-3 pm) includes a variety of activities. Pre-registration is required. Call for details. There is no charge for admission to any of the events.