The Sap Run

Filtering Syrup, Barnet, 1977. Photo Credit: Richard W. Brown

A friend recently quipped that New England's seasons are defined by swapping different types of waterproof boots out. But the surest sign of spring here is the sap run. Maple sap begins to run when the nights are freezing, and the days are warm. This cycle of freezing and thawing creates pressure changes in the tree. Those push sap out during the day and draw water in through the tree's roots at night. The longer the nighttime temperature is below freezing, the longer the sap will flow during the day. Sap runs best when days are in the 30's and 40's. When days are below freezing the sap will stop running. When they get too warm, and nights stay above freezing, the sap dries up. It is a tight window.

Maple sugaring first began with the natives of the northeastern United States and Canada. Historians believe that at some point in the past they began cutting bark from maple trees, to avoid starvation by eating the cambium. An edible layer between hardwood and bark. The cuts would have caused sap to flow from the tree. Which they might have collected to cook other foods in. Thus, discovering what happens to the sap when boiled down. Soon they began to collect the sap alone. Making a V shaped cut into the bark and inserting a wooden wedge into the bottom. Sap would flow out of the wedge dripping into wooden bowls or birch baskets placed at the base of the tree. They would then boil it down to a thick syrup and cool it to store in the baskets.

European colonists learned how to tap maples and boil syrup soon after arriving in the new world. French explorer Jacques Cartier was the first white man to make an account of the "couton" tree as the sugar maple was called in the native tongue. Rather than a cut in the bark colonists used augers to drill holes in the tree. Which they would drive a wooden spout into, and hang a bucket made from a hollowed-out tree segment to collect the sap. Sugarers pulled larger vessels of sap to a sugar shack where they boiled it down to make syrup and maple sugar. Which was popular at the time because of the expense of importing cane sugar.

But with increased availability of cane sugar in the 19th century sugar makers focused on syrup and there were many innovations which sped up the process. Around the middle of the century flat metal pans became available. These increased surface area over the iron kettles used before. Which allowed for more efficient heating and better evaporation. Two pan evaporators which allowed you to boil more sap came out in the late 1800's, then around 1900 fluted bottom pans which increased the surface area even more. The 20th century brought mechanization and scale to the sugaring process, but the basic technology did not change for decades. But in the 1970's producers started using reverse osmosis filtration to remove water from the sap and decrease boil times.

If you talk to the old timers, and I do, they will tell you this makes for an inferior product. The only thing that produces maple flavor is the caramelization of sugars during the boiling process. So, a shorter boil will result in a lighter syrup with less complex flavor. Despite identical sugar content. Then, of course, maple syrup also has terroir much like fine wine. Causing syrups from different regions to taste different. The composition and drainage of the soil, climate, and the topography of a region all influence the flavor. Which may be why New England maple syrup is so prized. To the point that a Canadian corporation sells "Vertmont" maple syrup in Europe to trade on its cache.

Next weekend Saturday, March 15th and Sunday, March 16th, 2025, is Maple Weekend in New Hampshire. It is an annual event when sugarhouses throughout the state open their doors to the public to teach them about the tradition and craft of maple syrup. It is a time when Yankee pride is on full display. If you are ever in the northeast when it is going on you should make a point to go. Maple syrup is a uniquely North American agricultural product, which evokes the charm of the iconic culture which created it. It speaks of agency and tastes of warm hospitality. You should accept no substitutes.