video, photograph, and text by Polly Saltonstall

Some people think frost heaves are the first sign of spring in Maine. I think spring starts much sooner, when the maple sap runs. There’s nothing quite like the first little rush of cold, sparkly liquid out of a freshly installed spile, and the delicious plink it makes when it hits the bottom of the bucket. (For those of you who may not know, a spile is the technical word for the spouts inserted into maple tree bark to extract the sap.)

I tap about a dozen trees in the woods behind my house, hiking out back to collect the sap morning and night. Rarely am I alone on those forays. A resident barred owl hoots to me in the late afternoon, smaller, earthbound critters scurry across the snow, leaving pointy footprints. The drip of the sap is a harbinger of the faster drips of melting snow inching into small streams and into the river and out to Penobscot Bay. The rush of the water sings out: “spring is coming.” My soul hears the song and sends my spirit joyously whirling into the current.

This is my third year tapping maple trees. The process of learning how to identify a sugar maple, and then how to collect its sap, as well as what makes the sap flow has been lovely way to enhance already regular walks in the woods. Sugar maples, or rock maples as old timers call them, feature a distinctive bumpy gray bark, especially when they are smaller. The final key to a positive id is to dig in the snow and find a leaf. Sugar maple leaves have smoothly rounded grooves between their lobes, unlike other maples’ sharp, serrated points and indents. The key thing for me is that looking around the woods with a purpose frees my mind from other worries. It forces me to live in the moment—a meditation of sorts.

Maple sap starts running when daytime temperatures start to rise, but nights remain below freezing. The fluctuation in temperature is what makes it all work. My understanding of the exact science is a bit fuzzy. One extremely simplified explanation is that sap flows through straw-like cells in the outer bark, which are surrounded by cells containing carbon dioxide. During the day warm temperatures expand the carbon dioxide, creating pressure inside the tree. When the tree is wounded, or tapped, the pressure forces the sap out. At night, or when temperatures drop below freezing, the gasses cool and contract, this creates suction in the tree, which draws water up from the roots, recharging the system. That water freezes, trapping and contracting the gasses even more. The cycle renews when warm daytime temperatures melt the ice and expand the gasses, creating pressure once again.

Whatever the cause, the sap in my woods is running. These trees and I have a pact. I talk to them and they talk back: plink, plink into my bucket.

Sap fresh from the tree tastes clear and cold, like water, but with a subtle backbeat of sweetness. It takes a lot of boiling to condense that hint into something more. Depending on the sugar content of the sap, it can take anywhere from 40 to 60 gallons to make one gallon of syrup. That’s a lot of boiling and a lot of steam. But the resulting gift from the woods will last until next spring when the cycle starts all over again.