Scientists from the University of Washington are testing the viability of making maple syrup in the Pacific Northwest. Long associated with Canada or Vermont, this sweet forest product that has graced many a breakfast table may be part of this region’s future.

Washington maple syrup is made from the watery-looking sap of bigleaf maple trees, one of the most abundant native hardwood trees in the Pacific Northwest. Given the right winter weather conditions, bigleaf maples — even here in Western Washington — can be utilized for their sap.

Researchers with the UW School of Environmental and Forest Sciences are proving this concept in a pilot project at the university’s Pack Forest near Eatonville, Washington. As part of a research initiative funded by the U.S. Department of Agriculture’s ACER program, they are producing syrup and measuring factors that might affect bigleaf maple and their sap. This winter, the project expanded to six additional sites across Western Washington, where private landowners were given seed grants to begin collecting sap on their properties.

“This is an exciting project,” said Indroneil Ganguly, project leader and associate professor in the School of Environmental and Forest Sciences. “We are on the cusp of a really, really big maple syrup industry in the Pacific Northwest.”

Winter 2019 was the first time that maple sap was collected at Pack Forest. The most productive time of year for sap collection is from about late-November to mid-February, when temperatures dip below freezing. Freezing conditions followed by a warm spell build pressure in the tree trunk. When the bark is drilled through and the tree is “tapped” — seen in this video with black plastic plugs that connect to delivery lines — the pressure forces maple sap out of the tree and down the tubes.