A sugar maple tree is usually 40 years old and should have a diameter of at least 10 inches before tapping.

The mapling season begins between February 15 and March 1. Warm sunny days and freezing nights determine the length of the maple season, usually between April 1 and April 10.

There are approximately 1200 maple trees that are tapped in the Village of Shepherd. So with an average rate of 2 taps per tree, Shepherd has about 2400 taps.

Maples that are tapped grow on village property between the sidewalks and streets. Most of the trees are within a 6-block by 5-block area within the village. If homeowners prefer not to have the trees in front of their house tapped, we oblige. Many homeowners give permission to tap the maple trees farther back in their yards.

There are several types of maple trees that can be tapped. The sugar maple, often called the hard maple, has the highest sugar content. Other kinds are the red maple (often called soft maple), silver maple and norway maple.

While many maple producers use plastic tubing under vacuum in their woods, instead of pails, to save time and the labor of carrying buckets though woods, Shepherd uses pails on the trees to collect the sap.

A hole is drilled into the tree at about a 2 inch depth, then a spile is pounded in at a depth of an inch and a half. Next, a 4-gallon pail is attached to the spile and finally a lid is placed on top.

Depending on the size of the tree, they hold up to 3 or 4 pails.

Sap from the sugar maple tree is a slightly sweet, colorless liquid and has about 2 – 3 % sugar content along with other nutrients. The rest is water. To make pure maple syrup, the sap must be boiled to evaporate most of the water. This occurs at approximately 219 degrees F or 7 degrees above the boiling point of water.

Tapping maple trees properly does not affect the health of the trees.

Some trees in maple country have been tapped for more than 100 years. In Shepherd that number is 50 years for many of the old, larger trees.

The number of sap run days varies from year to year but is usually between 15 and 20 days.

During a good “run,” the sap flow in one day could be a full 4-gallon bucket or more for some taps. Other runs might produce only a gallon or so but all sap must be collected and evaporated daily.

The key to good syrup production is to get the clear sap that has just run to the sugar house and evaporator as soon as possible for boiling

Through the whole mapling season, a given tap hole will average a total of 10 to 12 gallons of sap. This translates to 1 quart of pure maple syrup after boiling using the rough rule of 40 gallons of sap to produce one gallon of maple syrup. Some trees will yield much more than that.

Since each tap yields on average 10 gallons of sap (= a quart of syrup), the village-with its 2400 taps-yields 24,000 gallons of sap and 600 gallons of syrup.

Several times in the season, the yield on a super day in Shepherd can reach 3,000 gallons of sap collected.

Many area sap producers bring us their sap and are paid a rate based on the sugar content of the sap. The Stanton, Michigan, Lions Club is a large contributor.

Many volunteer helpers are needed to help collect the sap, boil, can, etc.

The budding of maple trees makes the maple syrup taste bitter. Production ceases at the time buds appear.

When the season is over, the pails and spiles are removed and washed.

Every year a new tap hole is drilled several inches from the previous hole.

Tacked on the beams of many sugar houses around maple country is the “Rule of 86.” C.H. Jones, a chemist at the University of Vermont, is credited with devising the Rule of 86 in the early 1900’s. It was a result of research on maple sap flow, sugar content of the sap and the carbohydrate contents of the maple tree. It is an easily stated rule and is known as Jones’s Rule of 86.

RULE OF 86 : Divide the percent sugar content of sap into 86 and you will get the number of gallons of sap required to produce one gallon of finished maple syrup. For example, if the sap has a concentration of 2.2%, then it takes about 86/2.2 = 39 gallons of sap to produce one gallon of syrup. A sugar content of 2 % would say that you would need 43 gallons of sap to make a gallon of syrup; 3% sap would require 29 gallons to make one gallon of syrup. Thus people just say that on average about 40 gallons of sap are required to produce 1 gallon of standard density syrup.

Only the water is boiled away. Maple syrup is 100% pure-no-additives, no coloring and no preservatives.

A gallon of syrup weighs 11 pounds.

An evaporator is used to boil the water away. Many creative methods have been introduced into the maple industry to speed up the time of boiling. These include reverse osmosis, which can remove up to two-thirds of the water before the sap reaches the evaporator, and pre-heaters, which use the steam of hot sap to heat the cold sap that enters the evaporator.

The production of pure maple syrup is the oldest agricultural enterprise in the U.S.

Maple syrup is the first farm crop harvested each year.

Sugar maples grow naturally only in southeast Canada, northeastern United States, and north midwest U.S.

Michigan is ranked 5th or 6th in the US for maple syrup production.

The top producing states are Vermont, New York, Maine, Ohio, Michigan, Pennsylvania, and Wisconsin.

The Shepherd Sugar Corporation is a member of the Michigan Maple Syrup Association. MMSA is an organization of over 200 maple producers in the state. The annual meeting in January consists of a full day of attendance at maple industry seminars and viewing displays of equipment and supplies. The late September meeting is the Fall Tour when five or so sugar bushes are visited in a specified area of the state.

People have been collecting sap from maple trees for centuries. Yet, why and how maple sap flows is quite a complicated question and a thorough understanding of the process by botanists and plant physiologists is quite recent (within 50 years). Research has been done on this question at many maple research centers in the U.S. and Canada, including at Cornell University and the Proctor Maple Research Center of the University of Vermont. Proctor was started in 1947 and is located on the lower slopes of Mt. Mansfield near the town of Underhill and close to Burlington.

WHAT CAUSES THE SAP OF THE SUGAR MAPLE TO FLOW IN THE SPRING?

The following explanation is based on what is known at the present time about the mystery of sap flow. Most trees wait until the forest ground is warm to begin their sap flow. However, the maple is unique in this regard. It starts its sap moving activity several weeks earlier in the spring in maple producing country when freezing nights but warming days occur. It is this freeze-thaw cycle that creates sap flow.

The sugar in the sugar maple tree is the result of carbohydrates produced by photosynthesis in the tree during the growing season of the previous year. The carbohydrates are stored as starch and then converted to sucrose and dissolved in the sap as spring arrives.

It was long thought that maple sap is pulled up the tree from the roots on warm days. Studies have suggested that this is not true. Apparently, sap gets to the sapwood moving up from the ground below during the freezing spell, and the sap collected in the sap bucket during thawing comes from the sapwood in all directions – upward, downward and laterally, not just upward as was previously thought. This was demonstrated by studies done by James Marvin at University of Vermont. He injected red dye into a maple tree three feet below a taphole during a thaw, and reddish sap appeared out the taphole in about 30 minutes. When he injected red dye three feet above a taphole, he saw the same result.

During cold periods (temperature below freezing 32 degrees F) the sap in the maple tree freezes, and the internal pressure within the tree becomes less than the outside atmospheric pressure. This negative pressure (suction) causes water from the soil to be drawn through the sapwood upward from the roots. This will increase the sap volume available in the tree for the next thaw period.

During warm periods (temperatures above freezing 32 degrees F) the frozen sap in the tree thaws and a positive pressure is created, namely by the presence of carbon dioxide. This pressure causes sap to flow out of the tree through a tap hole. The pressure may be as strong as 20 lbs per square inch. During a good run drips could occur at a rate of 2 drips per second.