How Maple Syrup is Made
When the Acer saccharum, known as the sugar maple, starts waking up at the end of the winter, it makes sap to feed the buds that will make leaves. The sap produced by the maple tree comes from the root of the tree. Maple sap looks like a glass of water and tastes like water with a little sweetness. The sap runs when the night temperatures fall below 32 degrees Fahrenheit and rise above that temperature during the day. The changes in the temperatures build up pressure within the tree and the sap rises. Sunlight, no wind, wetness around the base of the tree is all helpful for a good sap run. The maple sugaring season can last between 3 to 6 weeks and starts around the end of February to the beginning of March. Tree tapping begins, when a pattern of the right weather is in the forecast. Currently, our 11,000 taps can take one to two weeks to tap.
To collect the sap, sugarmakers have several different systems for collection. The system used generally depends on size of the bush, lay of the land and workforce available. At the Carman Brook Farm we use a pipeline tubing system. Today’s tubing is made of food grade material and has an expected life of 10 years. The maple lines are left in the woods year round and maintained throughout the year for the next sugaring season.
Maple trees should be at least 8 inches in diameter before they can be tapped once. Larger, older trees will have 2 taps. Since sap runs in the outer edge of the trunk the tappers need to make sure that they don’t drill too far into the maple tree. Every tap creates a small scar in the tree and that section of the tree cannot be tapped again until the tree has grown in circumference and healed over the scar. Maple trees make a lot of sap and taking a little won’t hurt the tree. Our Forest Management Plan addresses tree health on the 160 acres of sugarbush assuring that they will live to a ripe old age of 200+ years.
Vacuum is used to draw the sap out of the tree to collection tanks around the woods. From there the sap is pumped back to the sugarhouse where it is kept in big tanks awaiting processing. As soon as we have enough daily sap collected we begin the processing of the sap into syrup. Maple sap will ferment and spoils with warm temperatures.
There are two tanks in the sugarhouse that collects the raw sap pumped in from the woods. Emergency storage is always kept handy as a fast, quick sap run can overflow the tanks. It takes approximately 40 parts sap to make one-part syrup with a sugar content of 66.9%. At the Carman Brook Farm the sugar content of our sap is 2.7%.
Since there is so much water in the sap, we use a reverse osmosis machine to extract about 75% of the water. Removing excess water saves time and energy resources. The concentrated sap is pumped overhead to a holding tank that is above the evaporator.
The evaporator is what we call the machine that makes the maple syrup since its main job is to evaporate water from sap. The heat that is applied brings out the color and the flavor of the syrup. Mother Nature is in charge of that and you can learn about the Grades of Maple Syrup here. The sugarmaker boils the sap to about 7 degrees above the boiling point of water. All this depends on barometric pressure changes and elevation to sea level so its good to have a hydrometer handy to know when you have reached the proper density of syrup.
Eventually, the temperatures warm up and the trees start to sprout buds signaling the end of the maple sugaring season. When the trees pop their buds, the flavor of the sap changes and the syrup that is produced has an off flavor. Just because the maple trees have ended their work, the sugarmaker is far from finished. Equipment in the sugarhouse and in the woods is cleaned and serviced. The taps in the woods must be pulled from the trees.