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Frequently Asked Questions (FAQ)

This page is intended to offer answers to frequently-asked questions about maple syrup; if your question is not addressed here, please feel free to email us at AskMaple.

Collection & Production
Plants, Pests & Disease
Nutrition & Recipes


How long have people been producing maple syrup from sap?
While accounts vary, historical records indicate that Jacques Cartier observed Native American tapping maple trees in 1540, and there is written observations of Native American maple sugaring – or transforming sap into maple sugar – in 1557.

How was maple sugar originally made?
Native Americans and early European settlers cut a slanting gash in a maple tree, placed a v-shaped chip of wood in the bark below the gash, and collected the sap from the wounds in buckets made of birch bark. The sap was then boiled down to sugar using a hollowed-out basswood log, throwing hot stones into the sap to evaporate the water.

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Collection & Production

Where is maple syrup produced?
Sugar maples only grow naturally in eastern North America, north of 35 degrees latitude and east of 95 degrees longitude, including northeastern United States as far west as Minnesota, and the Canadian provinces of Ontario, Quebec, New Brunswick and Nova Scotia. Canada produces about 80% of the world’s supply of maple syrup, with the United States producing the remaining 20%. Vermont controls approximately 35% of all U.S. maple syrup production or distribution, or roughly 7% of the world’s maple supply.

When does the sugaring season occur, and how long does it last?
The sugaring season typically begins in mid- to late-February, when temperatures rise above freezing for a few days, bringing about a physiological change inside maple trees that triggers the sap to flow. The length of the sap season varies depending on the temperature, but an average sugaring season is about six weeks. Most producers are done boiling by mid-April, when the night time temperatures remain above freezing and the tree buds begin to swell.

How many gallons of sap does it take to make maple syrup?
Using the “Rule of 86,” you can figure that the number of gallons of sap you need to produce one gallon of syrup is equal to 86 gallons divided by the percent of sugar. So if you start with sap that is 2% sugar, you would need to evaporate 43 gallons to water (86 gallons / 2% = 43 gallons) to make one gallon of syrup.

How much maple syrup does one tree produce?
The volume of sap produced during a single season can vary anywhere from 10 to 20 gallons of sap, or 1/3 of a gallon of maple syrup. The volume depends on the tree, weather conditions, length of the sap season, and the method for collecting sap – producers using gravity lines or buckets generally get 10-14 gallons of sap per tree, while producers using vacuum tubing generally get 15-20 gallons of sap per tree.

How big should a tree be in order to tap it?
A tree should be 10 to 12 inches in diameter when measured 4.5 feet above ground level.

How many taps can you place in one tree?
A healthy tree with a 10-17 inch diameter should have no more than one tap, a tree 18-24 inches in diameter should have no more than two taps, and a tree with a diameter greater than 24 inches in diameter should have no more than three taps. For sap collected using a vacuum, it is recommended to use one 5/16 tap per tree, regardless of size.

How deep should tap holes be?
Tap holes which are 1-2 inches measured from inside bark are deep enough to ensure good sap yields; there is very little production advantage to drilling holes deeper.

What are the different methods for collecting sap?
Sap can be collected using buckets or tubing. Flow through tubing can be by gravity or enhanced through the use of a vacuum.

How is plastic tubing used for collection of sap?
A plastic tubing system may be set-up with main lines (from ½ to 2 inches in diameter), into which smaller (5/16 inch in diameter) tubes are joined to bring sap directly from the trees. The sap may flow by gravity, depending on the geographical layout of the sugarhouse, but more often a vacuum pump is used to create suction in the tubing to increase the flow of sap.

How does sap flow?
Sap flows through a portion of the outer tree trunk called sapwood. Sapwood consists of actively growing cells that conduct water and nutrients (sap) from the roots to the branches of the tree. During the day, activity in the cells of sapwood produces carbon dioxide, which is released to the intercellular spaces in the sapwood. In addition, carbon dioxide that was dissolved in the cool sap is released into the spaces between the cells. Both of these sources of carbon dioxide cause pressure to build up in the cells. A third source of pressure is called osmotic pressure, which is caused by the presence of sugar and other substances dissolved in the sap. When the tree is wounded, as when it is tapped by a maple produced, the pressure forces the sap out of the tree. At night or during other times when temperatures go below freezing, the carbon dioxide cools and therefore contracts, forcing the sap out of the tree. Some of the carbon dioxide also becomes dissolved in the cooled sap. Finally, some of the sap freezes. All three of these factors create suction in the tree, which causes water from the soil to be drawn up into the roots and travel up through the sapwood. When temperatures rise above freezing the next day, sap flow begins again.

How does sap become syrup?
During evaporation, sap is concentrated to the desired sugar content and the chemical changes that occur during the heating process cause the color and flavor of maple syrup to develop. Boiling time and microorganisms in the sap cause syrup to darken; reducing boiling time and killing microorganisms through UV treatment can help produce a lighter-colored syrup.

How does an evaporator work?
Sap is fed into an evaporator unit and kept at a constant level by a float. Evaporators can be heated by a variety of fuel options, including wood, oil and natural gas. The sap moves up and down channels in the evaporator unit, becoming darker as it becomes more concentrated. It eventually passes to a flat pan, is drawn off and is passed through a filter. The pans have covers on then with stacks to take the steam away through the sugarhouse roof; this leaves the air clean in the building and prevents unwanted materials from falling into the boiling sap. Many evaporators now have a pre-heater steam hood, which raises the temperature of the cold sap from about 35 degrees F to 190 degree F using the steam from the flue pan, saving both time and fuel.

How long does it take to boil one gallon of sap to syrup?
This depends on the size and efficiency of the evaporator. A small evaporator (2 feet by 6 feet) may boil 25 gallons of sap per hour, while a large evaporator (6 feet by 18 feet) may boil 380 gallons per hour.

How do you determine when syrup is finished?
A thermometer is used to tell when the temperature is high enough to indicate that the syrup is finished. This temperature will be 7.1 degrees F above the boiling point of water at that place and at that time. Since the boiling point of water varies, depending on atmospheric pressure, it must be computer at least once a day. A density of 66.7 degrees Brix is reached at the above mentioned temperature.

How much energy does it take to make maple syrup?
It usually requires approximately 3 gallons of fuel oil to make 1 gallon of maple syrup using an oil-fired evaporator. When hardwood fuel is used, a standard cord (4 feet by 4 feet by 8 feet) will produce enough heat to make approximately 15 gallons of maple syrup.

Does a producer need to register with any government agency in order to produce or sell maple products?
No, registration is not currently required to produce maple syrup. Those selling maple products must label them with the proper grade, as well as the name and address of the producer. There are different labeling regulations for each state; your state’s Department of Agriculture should be able to provide copies of the regulations for labeling maple products.

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Plants, Pests & Diseases

How many kinds of maple trees are there? Can they all be tapped?
There are over 100 varieties of maple tree (genus Acer), but only the sugar maple (Acer saccharum) has a high enough concentration of natural sugar to easily make maple syrup. Other maple varieties, including the black maple (Acer nigrum), red maple (Acer rubrum), and silver maple (Acer saccharinum), have been tapped in various parts of Canada to produce syrup.

How do you identify sugar maple trees?
Sugar maple trees are usually found growing on well-drained or moderately well-drained soils. The leaf of the sugar maple has five distinct lobes and a very smooth surface on the underside of the leaf. Sugar maples also tend to have more prominent fall colors of red and orange, while other species of maple tend to turn brown or yellow.

Does tapping negatively affect the health of a tree?
When done following proper guidelines, a healthy, undamaged tree will not suffer any adverse health effects and will remain productive.

Where does the sugar in the sap come from?
Sugar is produced in the leaves of the tree during photosynthesis. It is transported into the wood and stored during the winter, mostly in the form of carbohydrates, and is then converted into sucrose and dissolved into the sap.

What is sugarbush management?
Sugarbush management involves thinning the trees to improve the health of the woodlot and the sap producing potential of individual maple trees. The development of wide and deep crowns is encouraged to support the production of large volumes of sweet sap. The types of trees removed in improvement operations include: non-maple species, including hemlock, beech and ash, which interfere with the growth of maple crop trees; over-mature trees; diseased, dying and defective trees; and trees producing sap with a sugar content of less than 1%.

What factors affect the health of a sugarbush?
There are many factors that can adversely affect the health of a sugarbush, including insect defoliation, drought, grazing and lack of management. These factors can be especially damaging if they occur together over a period of several years.

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Nutrition & Recipes

What does maple sap look and taste like?
Maple sap is a clear liquid that contains approximately 2% dissolved sugar. It looks similar to water, and has a slightly sweet taste. Maple flavor develops through the process of heating and boiling.

What is the shelf-life of maple syrup?
If left unopened, the shelf-life of maple syrup is approximately one year. Once opened, the shelf-life of maple syrup is approximately six months, refrigerated.

What is the best container to store maple products in?
Plastic containers are inexpensive, but do allow some gas exchange that causes decreases in syrup quality; syrup in plastic containers will degrade and change color about one grade after 3 to 6 months of storage. Glass, while more expensive, retains syrup quality longer.

How do I substitute maple syrup for sugar in cooking?
Use 1 cup of maple syrup for 1 cup of white sugar in cooking, but reduce the liquid in the recipe by 3 tablespoons for each cup of syrup used. Maple sugar can replace white sugar in equal amounts.

What is maple cream and how is it made?
Maple cream, also known as maple butter or maple spread, is made from maple syrup that has been heated to 22 to 24 degrees F above the boiling point of water. It is cooled rapidly to about 50 degrees F and then stirred continuously until creaming is complete. It becomes maple cream because of its smooth and creamy texture, not because butter, cream or other additives.

How is soft maple sugar made?
Maple syrup is heated to 32 degrees F above the boiling point of water, cooled to 155 degrees F, stirred until crystallization starts, and then poured into molds.

How is hard maple sugar made?
Maple syrup is heated to between 40 to 45 degrees F above the boiling point of water. It is stirred immediately until crystals form, and then poured into mold.

How is maple sugar on snow made?
Maple syrup is heated to between 22 to 49 degrees F above the boiling point of water, depending on whether the sugar on snow if to be soft or hard. The hot syrup is poured in strips on well-packed snow and picked up with a fork or stick,

What is maple flavor?
There are over 300 different natural compounds found in pure maple syrup, but only one compound (sugar furanone) is linked to maple flavor that is present in all maple syrup. Other flavors in maple syrup can include: caramel, vanilla, nutty, buttery, floral (honey), chocolate, and coffee.

Does syrup taste and quality vary by maple production region?
Syrup flavor is affected by a variety of conditions, including tree genetics, soil type, weather conditions during the sugaring season, and processing techniques.

What is the difference in maple syrup grades?
Most maple-producing states and provinces have their own laws regulating syrup sold in those states; Vermont requires a minimum sugar content of 66.9% sugar in its maple syrup, while New York requires a minimum of 66% sugar. States that don’t have specific regulations must follow the USDA guidelines. All states must use the USDA color standards to grade - or classify - the maple syrup, although states are free to use their own words to describe the colors. Canada uses slightly different color standards, which leads to slightly darker syrups in each color grade.


United States (USDA)


No. 1 Extra Light

Grade A Light Amber


No. 1 Light Grade A

Grade A Medium Amber

Medium Amber

No. 1 Medium Grade A

Grade A Dark Amber

Dark Amber

No. 2 Amber

Grade B for reprocessing

Grade B

No. 3 Dark




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