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The Story of Maple Sugaring

The Sugaring Story Adapted from text compiled by the Vermont Maple Sugarmaker's Association
The Sugaring Season
Maple syrup making, known as “sugaring“ takes place all over the Northeastern U.S. and Canada just as winter is losing its grip. The maple producers or “sugarmakers“ look for weather that alternates between freezing and thawing; this is what makes the sap flow. In Vermont, sugaring weather usually starts around the middle of February and normally lasts for about six weeks. Snow may lay deep in the woods at the start of sugaring, but the warm sun on the branches of the maple trees causes the long dormancy of winter to give way and the sugaring season to begin. Visit a sugaring operation in the spring and you might see traditional, or modern methods of syrup making, or a combination of the two, as at Greene's Ox Pasture Maples. Regardless of the methods used, the basic principles are the same for all sugarmakers: sap is collected from trees, and then water is removed, mostly by boiling, to concentrate it into syrup. Nothing is added, and nothing is removed except pure water.
Maple sap
It all starts with maple sap. In the spring, maple sap contains a small quantity of the sugar sucrose. Sucrose concentration in sap is usually about 2% by weight, although this varies from tree to tree and ranges from 1% to over 4%. In addition, enzymes and other materials from the tree are present in very small quantities; these are what will give the syrup its unique maple flavor. The sap is collected by drilling one or more holes, called “tapholes,” into the trunk of the tree. The tapholes are small, usually, just 5/16” in diameter and only about 2” deep, and the sugarmaker takes great care to drill the holes sparingly so that the trees are not damaged and will continue to thrive for many generations. Trees that are about 10” in diameter (a sugar maple takes 40 years to reach this size) to 18” in diameter have one taphole; while larger trees may have 2 or 3 tapholes. Each hole is fitted with a plastic or metal spout so that the sap doesn’t just run down the bark. The spout goes into the tree for a short distance and conducts the sap into a bucket or into plastic tubing. The sap will drip from a hole in the tree when the weather conditions are right. A freeze will draw water into the roots from the soil and cause a small suction to be present in the wood. When the wood thaws, the sap is under pressure for a while and sap will emerge from the taphole.
Collecting sap with buckets
In Vermont, you might find sugarmakers who collect sap from 100 tapholes, or from 40,000. At Greene's Ox Pasture Maples we tap 13,000 plus. All the tapped trees together constitute the “sugarbush.” The traditional method of collecting sap is to hang a bucket on the metal spout. The sap fills the bucket, and every day, or several times a day, someone must empty the sap into a gathering tank on a tractor-drawn wagon, or perhaps a horse-drawn sleigh. This method is still used in many sugarbushes, especially those that have enough labor to empty all the buckets, or where land is very flat, or trees are too spread out to make plastic tubing practical. You will rarely see horses in the woods at sugaring time anymore.
Collecting sap with tubing
The more common method today is to collect sap with a network of plastic tubing that brings the liquid to a large collection tank. This saves the labor of going to every tree to gather the sap. Small diameter tubing runs from tree to tree, joining larger tubes called pipeline, or mainline, which conducts the sap downhill toward the tank. Many sugarmakers augment the flow of sap by attaching a vacuum pump to the tubing. This helps keep the sap moving in the tubing so that it arrives cold and clear at the sugarhouse. The use of vacuum also increases sap yield from each taphole, compared to the yield from buckets. Installing a tubing system can be a considerable undertaking for skilled individuals. Most tubing systems are left in the woods year-round, and the sugarmaker will spend many hours maintaining the system during the summer and fall, clearing fallen limbs and looking for animal damage. This continues right through the sugaring season when it is necessary to constantly check the whole system for any leaks that might appear.
The Sugarhouse
Whether by tubing, horse-drawn sleigh, or other means, the sap eventually ends up at the sugarhouse. The sugarhouse is the building where the evaporator is located, along with other equipment that may be used for syrup making. Some sugarhouses are quite small and rustic, with room for the evaporator and 2 or 3 visitors, while others are large and modern and might contain, in addition to the syrup making equipment, a large kitchen for canning syrup and making maple candy and other products. Every sugarhouse will have a cupola or large stainless steel chimneys to exhaust the great quantities of steam that are produced from the boiling sap; it is the sight of this steam that lets you know that an evaporator is fired up and the sugarmaker is making syrup.
Boiling the sap
Once the sap arrives at the sugarhouse, it must be boiled as soon as possible. Warm sap begins to break down, which will make darker, stronger tasting syrup; if not boiled soon enough, the sap begins to spoil. The boiling takes place in an evaporator, which consists of rectangular metal pans that sit on a large base called an arch, where the heat source is located. The evaporator may be as small as 2 feet wide by 4 feet long, or as large as 6’ x 20’, depending on the number of trees that are tapped in the sugarbush. Traditionally, sugarmakers burned wood in the arch to create the heat for boiling; today, many maple producers use oil as a heat source because it is convenient, and its use means less work than preparing the firewood. At Greene's Ox Pasture Maples we use the traditional wood-fired method. In any case, a very hot fire is needed to evaporate water from the sap. In the evaporator, the sap follows a winding path through the pans as it boils and becomes denser and closer to finished syrup. The sap first enters into the back or “flue” pan, which has deep channels, or flues, to maximize contact between the sap and the heat. The boiling is very vigorous and great quantities of steam are produced. Special float valves allow more sap to continually enter the flue pan as water is evaporated from the sap, and this keeps the sap level just right for efficient boiling. The sap then enters the front, or “syrup” pan, which is divided by metal partitions into 3 or more compartments, open at each end. As the sap moves through the syrup pan, it continues to increase in density as more and more water is boiled off. When it reaches the end of the pathway and is at just the right temperature (7.1 degrees above the boiling point of water) and density (66.9% sugar) the sap has turned to pure maple syrup The sugarmaker must now open a valve and draw off a batch of this liquid from his pan before it gets even denser and burns. 
Finishing the syrup
Once a batch of the syrup has been drawn off, there are several more steps before it is stored. First, it is checked for the proper density (sugar content) with an instrument called a hydrometer. The hydrometer is floated in a cup of syrup, and it is calibrated to balance at a certain point when the density of syrup is correct. After this, the syrup must be filtered to remove a gritty substance called “sugar sand” or “niter.” Sugar sand is a natural, harmless material made of minerals from the maple tree that precipitate in the syrup pan as the sap is boiled. To remove it, the hot syrup is passed through a wool cone filter or pushed by a pump through a filter press. It comes out clear and golden, ready to be consumed, or packaged. Now the syrup is taste-tested and color graded, to determine which of the Vermont grades (Golden with Delicate Taste, Amber with Rich Taste, Dark with Robust Taste, or Very Dark with Strong Taste) will be on the label. At this point the sugarmaker will usually fill a steel drum with the hot syrup, to be stored and then opened later for repacking into small retail containers.
New Technology
In a modern sugarhouse, you may also see some of the new technology that helps the sugarmaker be more efficient in his syrup production. One of the most interesting pieces of equipment is the reverse osmosis machine. This works like a water purifier in reverse, pushing the sap through a fine membrane to separate pure water from the sugar, and thus concentrate the sap before it is boiled. Reverse osmosis can remove ¾ of the water from the sap, which saves the sugarmaker a great deal of time in boiling. Another modern innovation is the steam recovery device, which is a large metal box that sits over the flue pan and uses the tremendous steam energy rising from the pan to preheat the incoming sap, and start the evaporation process. In addition, this becomes a source of clean hot water. Some sugarmakers use an electronic instrument that can open the draw-off valve at just the right time for the syrup to be released at the proper density.
“Liquid gold”
Whether you visit a sugarbush and sugarhouse that uses traditional or very modern techniques, or a combination of the two, you will see people hard at work during the spring when the sap is running. Sugarmakers are very proud of their operations and are usually pleased to point out to visitors the many features, some of which may be unique and of their own invention, that are involved in the process of making syrup. While you are visiting, you will have a chance to taste and purchase syrup or other maple treats that the sugarmakers produce, made more special by an understanding and appreciation for what it takes to create “Vermont liquid gold.”