How Maple Syrup is Made

The "Maple Story" of Pure Vermont Maple Syrup

The Sugaring Season

Making maple syrup is known as “sugaring“ & takes place across the Northeastern U.S. and Canada in the spring.  The maple producers are called “sugarmakers“.  The appropriate weather for sugaring season is that which alternates between freezing and thawing. This is what makes the sap flow.  In Vermont, sugaring weather usually starts around the beginning of March, and normally lasts for about six weeks. Snow is deep in the woods at the start of sugaring.   With the warmer weather, the maple trees awaken from their long dormancy of winter and the sugaring season begins.  Visit a sugaring operation in the spring and you might see traditional or modern methods of syrup making.  The basic principles are the same for all sugarmakers - sap is collected from trees,  water is removed from the sap by boiling - concentrating it into syrup. Nothing is added.  The boiling process brings out the color and wonderful maple flavor. 

Maple Sap

In the spring, maple sap contains a small quantity of the sugar sucrose. Sucrose concentration in sap is usually about 2%, although this may vary from tree to tree and ranges from 1% to over 4%.  Sap is collected by drilling one or more “tap holes,” into the trunk of the tree. The tapholes are small, usually 5/16” in diameter and about 2” deep.  The sugarmaker takes great care to drill the holes sparingly so that the tapping will not affect the health of the tree.  These trees will continue to thrive for many generations. A sugar maple takes 40 years or more to reach the proper size for tapping.  Trees that are 10” in diameter to 20” in diameter have one taphole. Larger trees may have 2 or 3 tap. A plastic or metal spout is placed into each tap hole & conducts the sap into a bucket or plastic tubing. The sap will run when the weather conditions are above freezing.  A freeze will draw water into the roots from the soil and cause the sap to rise and travel up the tree. When the wood thaws, the sap is under pressure and sap will emerge from the taphole.  In Vermont, you might find sugarmakers who collect sap from 100 taps or from 40,000. A large group of maple trees is called a “sugarbush.”

Collecting Sap with Buckets

The traditional method of collecting sap is to hang a bucket on the metal spout. The sap fills the bucket, and every day, someone must go to each tree to gather the sap.  It is hard work to empty all the buckets.  It is a rare but special treat to see someone gathering sap with horses!

Collecting Sap with Tubing

The more common method today is to collect sap with a network of plastic tubing that brings the sap 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 mainline, which conducts the sap downhill to the holding tank. Installing a tubing system can be a considerable undertaking. Tubing systems remain in the woods year round.  The spouts are removed from the tree after the season is done.  The sugarmaker will carefully clean the system directly following the season.  During sugaring season, it is necessary to frequently check the tubing system for any leaks that might appear.

 
The Sugarhouse

Whether by tubing, truck, tractor or  horse drawn sled, the sap arrives at the sugarhouse. This is the where the evaporation of the sap takes place.  Some sugarhouses are quite small and rustic, while others are large and energy efficient production facilities. In addition to the syrup making equipment they may have a large kitchen for canning syrup, making maple candy and other wonderful maple products. Every sugarhouse will have a cupola to vent the great quantities of steam that are produced from the boiling sap.  When you see the steam rising and smell the faint sweetness of the syrup on the breeze, you know that an evaporator is fired up & sugaring season has begun!  Visitors are always welcome!

Boiling the Sap 

Once the sap arrives at the sugarhouse, it must be boiled as soon as possible to produce the highest quality maple syrup.  The boiling takes place in an evaporator, which consists of stainless steel pans that sit on a large base called an arch, where the heat source is located. The evaporator may be as small as 2' x 4' or as large as 6’ x 20’, depending on the number of trees that are tapped in the sugarbush. Evaporators can be fired with wood, oil or propane.  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 thicker. The sap first enters the “flue” pan, which has deep channels to maximize contact between the sap and the fire. The boiling is very vigorous and great quantities of steam are produced.  The sap then enters the “syrup” pan, which is divided into 3 or more compartments. As the sap moves through the syrup pan, it continues to increase in density as more water is boiled off.  When the syrup reaches the draw off point, the temperature is 219 degrees (7.1 degrees above the boiling point of water) and density (66.9% sugar).  The sugarmaker must now open a valve and draw off the finished syrup.

The final step

Once a batch of syrup has been drawn off, it is checked to assure the proper density (sugar content) with an instrument called a hydrometer. The hydrometer is a floating device that measures the specific gravity or density of the syrup.   After this, the syrup must be filtered to remove a gritty substance called “sugar sand” or “niter.”   Niter is the natural occuring minerals from the maple tree that precipitate out as the sap is boiled. To remove it, the hot syrup is passed through filters.  It comes out clear and golden, ready to be packaged. Now the syrup is taste tested and color graded, to determine which of the Vermont grades:Fancy, Medium Amber, Dark Amber, or B - will be on the label.  The sugarmaker will package the syrup into retail containers or large food grade drums.  This allows the syrup to be stored for later use.

New Technology

In recent years, the rising cost of energy has encouraged the use of new technology to help sugarmakers become more efficient.  In a modern sugarhouse you will likely see a reverse osmosis machine. This works by pushing the sap through an extremely fine filter to remove large amounts of  water from the sap, reducing boiling time and fuel usage.  Another modern innovation are several different types of pre-heating and pre-evaporation hoods & pans which use the tremendous steam energy rising from the boiling pans thus increasing efficiency. These also condense the steam, providing large quantities hot water for cleaning purposes.

“Liquid Gold”

Whether you visit a sugarhouse that uses traditional or modern techniques, or a combination of the two, you will see people hard at work during the spring when the sap is running. Sugarmakers have always been proud of their craft and the products they make. There is nothing quite like the taste of syrup warm from the evaporator.  Enjoy this springtime tradition where you will gain appreciation for what it takes to create “Vermont's liquid gold.”