What Makes the Sugar Maple Tree so Sweet?

In Summer…

Bright green leaves on sugar maple trees combine sunlight, carbon dioxide from the air, water and soil nutrients through photosynthesis to produce food energy for tree growth.

Fall Frosts…

Bring on spectacular leaf color displays causing food energy to be converted into starch.

In Winter…

Trees store the starch in root tissues waiting for the warm sunlight of Spring to touch their branches. The starch is then converted into sugar, an energy boost for young leaves to be produced. This sugar mixes with moisture from the ground within the trees to form sap.


Prior to European Settlement in North America

While modern research and science has taught us so much about producing maple syrup and why exactly it’s healthier than any other all natural sweetener, it is still unknown who deserves the credit for making the first batch of maple syrup. The following legend however, is the most commonly told.

Prior to the European settlement of North America Chief Woksis of the Iroquois tribe was said to have thrown his tomahawk into the trunk of a maple tree. The next morning he pulled his tomahawk out of the tree and went off hunting for the day. The tree began to thaw on that warm spring day and the wound left in the tree by the tomahawk filled a container left at the base of the tree. When the chief returned from hunting his wife began to prepare their dinner thinking the container of tree sap was water using it to cook their dinner. After cooking the food for a period of time they came to find it was delicious like no meal they’d had before. In attempts to recreate that delicious sweet taste, the tradition of making maple syrup began.

It is believed during these times tomahawks were used to carve downward pointing arrows into the trunk of maple trees. This allowed the sap coming out of the trunk to flow down and be collected into birch bark buckets. The boiling down of the sap is believed to have been done by filling carved out logs with sap and putting in rocks heated by fire.

Post-European Settlement

When European settlers met up with these natives who were producing maple sugar they introduce the metal kettle to the syrup or sugar making process. This drastically increased the efficiency of the process and allowed pioneers in the northeast to produce a years supply of sugar self sufficiently.

In the early years of the United States maple was promoted by very prominent men such as Benjamin Franklin because it made the United Stated less reliant on foreign sugar sources. Most of the foreign sugar was produced by slave labor in western India at the time. Thomas Jefferson also is credited with promoting maple sugar as a “home grown” alternative to foreign produced sugar.

In the early 1800’s the creation of wooden spouts made for a much less intrusive way to gather the sap from the tree. During this period the price of pure maple sugar dropped below the price of imported sugar and the industry was starting to see much growth and innovation.

The mid to late 1800’s gave way to innovations such as the sugarhouse or sugar shack, the first maple evaporating pan, and the production of metal spouts. The sugarhouse or sugar shack was simply an outbuilding with the sole purpose of boiling down maple sap. The first maple evaporating pans were flat bottomed and highly efficient due to increasing the amount of boiling surface area. The metal spouts developed decreased damage done to the trees outer and inner bark. The spouts were also designed to hold up the gathering buckets which before the development of tubing systems was the only collection method.

Soon after the flat pan was developed

designs with flues in the pan started to come about. By having flues going up and down across the width of the pan it further increased the surface area for heat, therefore increased evaporation rates. Right here in the State of Vermont in the 1870’s the first true Evaporator was invented; consisting of two pans on top of a metal firebox. Almost 150 years later, this evaporator set up is still the most commonly found in sugarhouses across the country.

In 1893 the Vermont Maple Sugar Makers Association (VMSMA) was founded. The association consisting of maple sugar makers and packers was created to promote Vermont maple syrup and protect the branding of 100% pure maple products. VMSMA helped create industry wide standards pertaining to the quality of maple products. Our very own Pam Green is the Chair on the board of directors for the association.

The 1900s

The 1900’s brought more growth to the maple sugaring industry as well as more innovation. The first attempts to use tubing to gather sap were actually with metal pipes. Due to freezing and leaking issues these never caught on as well as the plastic tubing used today. Another common misconception is that the use of plastic tubing for maple collection is new. The first patent for for plastic maple pipelines was filed in the year 1959 by Nelson Griggs, a Vermonter. It didn’t take many years after using plastic pipeline before some farmers who were in both the dairy and maple industry to start to think about hooking their milk vacuum pumps up to the maple tubing system. This would provide a constant negative pressure on the tap hole increasing the amount of sap gathered. However, many of these innovations weren’t widely adapted or perfected until late in the 1900’s.

The 2000s and Beyond

By today’s standards, a sugar maple is usually at least 40 years old or 10 inches in diameter at chest height before the sugarmaker considers tapping it. We have a strict rule of only one tap per tree. When Spring temperatures reach 45º F during the day and nights remain below freezing (25º F is perfect), the sugarmaker drills a hole in the trunk of the tree and taps in a spout with either a hook and bucket or plastic tubing. Sugaring season has begun!

Sap averages 2-3% sugar concentration and looks like clear water. The sugar concentration of maple syrup is 66.9%. The sugarmaker will gather around 40 gallons of sap to make each gallon of syrup. Each tap will yield a little over one quart of syrup during the season on average. Most spouts used today are 5/16 Health Spouts. These are less invasive and healthier for the trees than the 7/16 diameter spouts used in the past and don’t constrict the sap flow from the tree.

The sap is gathered and brought to the

sugarhouse where it is quickly boiled down. Most sugarhouses today are using reverse osmosis machines to cut down on fuel usage and labor boiling down the syrup. Once a portion of the water has been removed the concentrated sap goes into a tank. This tank is typically stainless steel and is above the evaporator so it can be fed into the back of the evaporator by gravity.  The concentrated sap then flows into the back pan. As mentioned above most evaporators today consist of an arch (fire box) topped with two stainless steel pans. The rear pan is larger and has flues to maximize the heat transfer and evaporation. When the sap is closer to becoming syrup it moves onto the front pan. Front pans are flat and don’t boil as extreme as the back pan. This gives the sugarmaker more control over the finished product and allows them to get it as close to 66.9% sugar concentration as required to be considered syrup by law. The fresh syrup gets filtered, graded, checked for density, and packed into stainless steel barrels for storage.

Up until recently wood has been the primary fuel used to boil down sap. In recent years many companies have left the tradition of burning wood behind in search of greater profits for their business. Many larger operations are currently using oil, propane, natural gas or other sources to create the heat required to turn sap into syrup. At Green’s Sugarhouse we are proud to be one of the few to carry on the tradition of burning wood.

The syrup season ends when warm Spring temperatures coax the leaf buds to unfold, leaving the sugarmaker to pull the taps,  and clean the equipment.

Click this link to learn more about what we do with all our maple syrup at Green’s Sugarhouse.