Maple Tree Health
(Frequently Asked Questions)
Frequently Asked Questions for the Maple Producer:
Syrup Collecting and Processing (below)
Frequently Asked Questions for the Maple Forest Owner:
Sugar Bush Management, Maple Trees, and Sap Flow
Frequently Asked Questions for the Maple Consumer:
Maple Syrup, Cream, and Candy
What is maple flavor?
Around 300 different natural flavor compounds have been found in pure maple syrup, though not all in the same syrup. Your nose detects most of these compounds. There is a compound linked to maple flavor that is present in all pure maple products, but varies in amount between producers and time of year. Other prominent flavors are sugars, caramel, and vanilla. Nutty, buttery, floral (honey), cereal, chocolate, and coffee flavors can be found in some syrups. As is the case for most natural products, maple syrups have complex flavor chemistry to delight your sense of taste and smell.
Does syrup quality vary from one region, state, or province to another?
Syrup flavor is affected by soil type, tree genetics, weather conditions during the maple season, time during the season when the sap is collected, and processing technique. Producers in every region consistently are able to produce good tasting, high quality products, but no region is always better than another. Pure maple is a natural product with considerable variation in flavors. Like wines, this variation should be sampled and enjoyed.
What is the difference in syrup grade?
Maple syrup must meet exacting standards for purity. High quality pure maple syrup can be made only by the evaporation of pure maple sap, and by weight may contain no less than 66 percent sugar (Brix). In Vermont and New Hampshire the minimum sugar content is 66.9%. Maple syrup is classified according to its color, which is a rough guide to flavor intensity. The darker the syrup, the stronger the flavors.
- New York Grade A Light Amber or Vermont Fancy — the lightest of the three classifications has a mild, delicate flavor
- Medium Amber — a bit darker with a fuller flavor
- Dark Amber — the darkest of the three grades has a stronger maple, caramel, and other flavors
- Grade B — has the strongest flavors
How does syrup grade vary for New York, Vermont, Quebec, and Ontario?
Most maple-producing states and provinces have their own laws regulating syrup sold in those states. States without such regulations must follow the U.S.D.A regulations. Vermont and New Hampshire require a slightly higher minimum density of sugar than is required by the regulations in other areas, though many producers use the higher density guidelines. All U.S. regulations use the U.S.D.A. color standards, but have different words to describe the colors. Canada uses different color standards, which leads to slightly darker syrups in each color grade. Following is a chart showing equivalent grade names. Syrups produced entirely within Vermont may have “Vermont” as part of the grade designation. Significant amounts of the syrup sold by Vermont companies are produced in other states and provinces.
1 Extra Light
A Light Amber
1 Light Grade A
1 Medium Grade A
B for reprocessing
syrup quality vary from one region, state, or province to another?
Syrup quality is affected by weather conditions during the maple
season, time during the season when the sap is collected, and processing
technique. Some producers in every region consistently are able
to produce light color, high quality products, but no one region
is better than another.
maple syrup produced all through the United States? The world?
Maple syrup is produced only in the northeastern United States and
eastern Canada, the region in which sugar maple is found. Although
maple syrup is not produced in other regions of the world, some
other species of maple are tapped. For example, in Korea, people
tap a maple species called Acer mono and pipe the sap from
the mountains down to the village. They drink the sap but do not
boil it to produce syrup. Birch trees may be tapped in Alaska and
Siberia but the sap is lower in sugar content and quality than maple
In cooking, what is the equivalent amount of maple syrup for white sugar? Can maple syrup be used as a substitute for sugar?
Maple syrup can be substituted for white sugar in cooking. Use 1 cup maple syrup for 1 cup white sugar. Reduce liquid in recipe by 3 Tablespoons for each cup of syrup used. Maple sugar can replace white sugar in equal amounts.
What is the shelf-life for maple products?
The shelf-life for maple syrup in a properly filled and sealed container is over one year. The shelf-life for maple syrup after initial opening is about six months in the refrigerator. The shelf-life for un-coated maple candy is about two weeks on the shelf or in the refrigerator, and for coated maple candy about six months at room temperature. (Coated maple candy should not be kept in the refrigerator.) The shelf-life for maple cream is about two months in the refrigerator, but it can be stored frozen for a long period of time.
Is the sugar in maple syrup healthier than white sugar?
The sugar in maple syrup is sucrose with small amounts of glucose and fructose sugar. White sugar is sucrose. There is no direct scientific evidence that maple syrup is healthier than white sugar. Diabetics need to treat maple syrup and sugar as they do other sugar products. Because it is a less refined sugar, maple products contain minerals, antioxidants, and other compounds that have been shown to have health advantages in other foods.
Is maple syrup organic?
The overwhelming majority of maple syrup is produced in forests
where no herbicides or pesticides have been applied. Therefore,
most maple syrup would be considered organic.
is required for syrup to be labeled "organic?"
The requirements are stated by the particular organic certification
organization, but generally state no use of substances (for example,
fertilizers or pesticides) in the production process that would
alter the pure nature of maple syrup.
long have people been producing maple syrup from sap?
Native Americans produced maple syrup before Europeans arrived in
Asked Questions for the Maple Forest Owner: Sugar
Bush Management, Maple Trees, and Sap Flow
many taps should you have on a maple tree?
A healthy tree 10-17 inches in diameter (31-53 inch circumference)
should have no more than one tap. A tree 18-24 inches in diameter
(57-75 inch circumference) should have no more than two taps. A
tree larger than 25 inches in diameter (79-inch circumference) should
have no more than three taps.
much sap does a single tree produce in one year, on average?
The volume of sap produced during one season varies from 10-20 gallons
per tap, depending on the tree, weather conditions, length of the
sap season, and method of collecting sap. Producers using gravity
lines or buckets generally get 10-14 gallons of sap per forest-grown
tree. Using buckets on roadside trees or using vacuum tubing yields
15-20 gallons per tap. A single tree can have one, two, or three
taps, depending on size and health.
what age does the quantity of the sap begin to slow down?
As long as the tree remains healthy, it should continue to produce
sap. Some trees have been know to produce sap for several farm family
generations, over 100 years.
tapping a tree affect the health of the tree in any way?
A healthy, undamaged tree that is tapped according to the guidelines
provided in Maple
Syrup Production for the Beginner
by Anni Davenport and Lewis Staats (also available through your
Extension office) will not suffer adverse health effects and
will remain productive.
the leaves of trees that have been tapped turn before those that
havent been tapped?
No, only trees that are stressed for various health reasons (for
example, fungal disease or drought) will turn colors first.
many trees would I need to produce 30 gallons of syrup per year?
of sap to produce one gallon of syrup = 86 / % sugar content in
of sap = 86/2Gallons
of sap = 43
This will vary depending on sugar content and size of the trees.
Lets say you have trees that average 2% sugar content and
you have trees large enough for two taps per tree. Using the "Rule
of 86," you know that the number of gallons of sap you need
to produce one gallon of syrup is equal to 86 divided by the percent
sugar of 43 gallons of sap.
Therefore, to produce 30 gallons of syrup, you need 1290 gallons
of sap (30 X 43).
For example, consider a sugar bush containing trees with two taps
per tree, each tap producing 10 gallons of sap, or 20 gallons of
sap per tree. To get the number of trees necessary to produce 30
gallons of syrup, divide 1290 gallons of sap by 20 gallons of sap
per tree. This is about 65 trees.#
of trees = total gallons of sap / gallons of sap per tree#
of trees = 1290/20#
of trees ~ 65
the sap of different maples (for example, sugar, red, Norway) different?
The sugar content of sugar maple sap is higher than the sap of other
maples. Sugar maple also produces syrup with the most pleasing flavor.
Once buds develop on the trees in the spring, syrup develops an
unpleasant "buddy" flavor. Sugar maple has the longest
period of sap flow before buds develop.
what age should a stand of maple trees be thinned?
The sapling stage is ideal for thinning maple trees as younger trees
are vigorous and respond to thinning dramatically. Thus, if a stand
is thinned at the sapling stage, the trees will reach tapping size
at a young age and with wide, deep crowns necessary for maximum
is the best spacing for maple trees in the woods to maximize tree
health and sap production?
The best spacing is about one tree in an area measuring 30 feet
x 30 feet, or 50-60 mature trees per acre. Initially, a maple grower
may start with a higher density of trees but will thin several times
to achieve a final density of 50-60 trees per acre.
tapping a tree change the value of the tree for lumber?
The bottom 4-6 feet or tapping zone will be reduced in value by
defects associated with tapping. Above this zone, the quality of
the wood will not be affected by tapping.
size should a tree be before tapping?
A tree should be 10 to 12 inches in diameter when measured 4.5 feet
above ground level.
do sugar maples produce the best syrup?
Sugar maple trees generally have sap with higher sugar content and
produce better flavored syrup than other maple species. Although
no one knows the exact reason for the higher sugar content, scientists
suggest it may be related to the structure of the wood. The sugar
is stored in the wood.
does the sugar come from?
Sugar is produced in the leaves during photosynthesis. It is transported
into the wood and stored during the winter, mostly in the form of
carbohydrates. It is then converted to sucrose and dissolved in
makes the sap rise?
During warm periods when temperatures rise above freezing, pressure
develops in the tree. This pressure causes the sap to flow out of
the tree through a wound or tap hole. During cooler periods when
temperatures fall below freezing, suction develops, drawing water
into the tree. This replenishes the sap in the tree, allowing it
to flow again during the next warm period.
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.
This carbon dioxide 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
producer, 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. 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.
This 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.
does the sap stop rising?
Once temperatures no longer fluctuate between freezing at night
and thawing during the day, sap stops flowing.
do sugar maple trees vary in sweetness?
Genetics and the environment both affect sap sweetness. Some trees
have one or more genes that cause sweeter sap. Environmental factors
including weather, the site on which the tree is growing, and whether
the tree is growing in the open or surrounded by other trees all
affect sap sweetness.
fertilizing maple trees make sweeter sap?
We do not know the answer to this question. We plan to undertake
a small research project to answer this question in the near future.
You may want to try your own experiment to answer this question.
does sweetness vary from year to year?
Sap sweetness has been observed to be lower in years following a
growing season when conditions were unfavorable for production of
sugar through photosynthesis. For example, if a stand is attacked
one year by insects that defoliate the maple trees, the next years
sap would be expected to be low in sugar. Some scientists have speculated
that a vigorously growing tree might use up so much of the sugar
produced by the leaves that it would have a lower sugar content
the following year.
vacuum tubing take too much sap from the tree?
No, properly installed vacuum tubing does not harm a tree.
used in answering FAQs:
North American Sugar Producers Manual. 1996. Edited by: M.R. Koelling
and R.B. Heiligmann. Ohio State University Extension, Bulletin 856.
section was written by Marianne Krasny. Contributors to this section
include: Laurel Gailor, Bob Beyfus, Lewis Staats, and Charles Winship
Asked Questions for the Maple Producer: Maple
Syrup Collecting and Processing
- How many taps should you have on a maple tree?
For sap collected under vacuum, we recommend one 5/16 tap per tree regardless of tree size. This will optimize long-term sap production through limiting internal compartmentalization and allow for tree growth to produce new wood over the tapped area.
For collecting sap without vacuum, more taps will be needed to produce the same volume of sap as vacuum. Tree growth rate affects the number of taps, but a conservative starting point a trees 10-17 inches in diameter (31-53 inch circumference) should have no more than one tap. A tree 18-24 inches in diameter (57-75 inch circumference) should have no more than two taps. A tree larger than 25 inches in diameter (79-inch circumference) should have no more than three taps.
is the average start-up cost for equipment in a small scale ("hobby")
Lets assume you plan on 150 taps (about 40-50 gallons of syrup)
and are starting out with new equipment. We will also assume you
have a building to use as a sugar house. The approximate costs
assume that you sell the 40 to 50 gallons of syrup at $32 per gallon
for a total revenue of $1300 to $1600 for the year. Then assume
a 50% gross profit or $800 per year. The break even cash flow year
is $4000/$800 = year 5. Not really a good deal if your only reason
for going into the maple business is profit! Used equipment would
reduce the capital cost by 30 to 75%.
$4 per tap X 150 taps
plastic storage tank
many taps would I need to produce 20 gallons of syrup per year?
A rule of thumb is 1/3 gallon of syrup per tap. Thus, you would
need about 60 taps to produce 20 gallons of syrup.
size evaporator pan do I need for different amounts of sap?
When deciding on the size of an evaporator, the maple producer should
consider the amount of sap to be processed, how quickly the sap
will be processed, amount of time available to process the sap in
any one day, future plans, and amount of capital available. For
example, if a producer has a 1200 tap sugarbush that will produce
1 gallon per tap in a good year, wants to process all the sap the
day it is collected, and has 10 hours in the day to process sap,
he or she can estimate the size of the evaporator as follows:
Number of sap gallons in run = 1200 taps x 1 gallon/tap = 1200 gallons
Time available for boiling sap = 10 hours
Evaporating capacity required = 120 gallons of sap/hour
The producer can then contact a maple equipment dealer to determine
the optimal evaporator size. Evaporator size varies from 2 feet
x 6 feet and a capacity of 25 gallons per hour, to 6 feet x 18 feet
and a capacity of 380 gallons per hour.
is the basic equipment that someone needs to get started in maple
The equipment needed depends on whether you are producing maple
syrup for home or commercial use. For home use, you will want to
have the following:
hand brace or breast drill with 7/16 inch diameter drill bit
(or spout), metal or plastic for each taphole
with cover, plastic sap collection bag, or plastic tubing (all food
or storage containers, such as plastic or metal trash cans (several
gallons in capacity and leak-free) for sap storage before processing.
Storage capacity of 1-2 gallons for each tap.
with high sides and a heat source for boiling sap. Stainless steel
with lead-free solder or welded seams strongly suggested. Heat source
can be wood fire, propane, or camp stove.
calibrated to at least 30oF above boiling point of water.
Kitchen or candy thermometers may be adequate but must be easily
readable above 200oF.
for filtering hot finished syrup (food quality)
for storage of the finished product (canning jars, syrup jugs, etc.)
of these supplies should be available from a local hardware store
in maple producing regions. Used equipment may be for sale in classified
ads in newspapers or agricultural circulars.
a commercial operation, contact a maple equipment dealer. If you
are having difficulties locating a dealer, contact your local Cooperative
there any maple groups or associations that I might join to find
out more about maple syrup?
Yes, most states have county, regional, and state associations.
Contact your local Cooperative
Extension office if you do not know the local contact.
can I purchase equipment to produce maple syrup?
You can purchase equipment from maple equipment dealers such as
Waterloo/Small, Leader Evaporator, G.H. Grimm, or Dominion &
Grimm. Contact your local Cooperative
Extension office for help finding these companies or look them
up on the Internet.
are the different methods for collecting sap?
Sap is collected using buckets or tubing. Flow through tubing can
be by gravity or enhanced through the use of vacuum.
is the most cost efficient fuel for producing sap? (Wood, oil, coal,
many years will an evaporator last?
Decades if used properly.
is the best container to put maple products in and why?
Plastic containers are inexpensive but allow some gas exchange that
causes decreases in syrup quality. Syrup in plastic containers will
degrade (change color) about one grade after 3 to 6 months of storage.
Syrup stored in plastic containers should be refrigerated. Glass
is more expensive and breakable but retains quality longer. Tin
was used commonly in the past and is still used to attract traditional
many gallons of sap are needed to produce one gallon of syrup?
of sap to produce one gallon of syrup = 86 / % sugar content in
This will vary depending on sugar content of the sap. The "Rule
of 86" is used to calculate the gallons of sap needed to produce
one gallon of syrup. It states that the number of gallons of sap
you need to produce one gallon of syrup is equal to 86 divided by
the percent sugar.
For example, you would need 43 gallons of sap with 2% sugar content
to produce one gallon of syrup.
process causes sap to become syrup?
During evaporation, sap is concentrated to the desired sugar content
and the distinctive maple color and flavor also develop. Chemical
changes that occur during heating cause the color and flavor to
Boiling time and microorganisms in the sap cause syrup to darken.
Reducing boiling time and killing microorganisms through UV treatment
can help to produce lighter colored syrup.
The development of flavors is not well understood, but it is thought
that amino acids in the sap play an important role.
a high sugar content change the boiling time? By how much?
Yes, the higher the sugar concentration of the sap, the less water
that needs to be removed to make syrup. Each time you double the
sap sugar concentration, you cut in half the amount of water that
needs to be removed and the boiling time. For example, sap with
4% sugar requires half the boiling time of sap with 2% sugar to
produce syrup. (You need 21 ½ gallons of 4% sap and 43 gallons of
2% sap to produce a gallon of syrup.)
the evaporator units constructed the same for different fuels?
Pans are generally the same design (except for differences between
different manufacturers). The arch, which is the structure that
supports the pan and contains the combustion chamber, is designed
specifically for the type of fuel.
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 proper grade and
name and address of producer. There are different labeling regulations
for each state. Contact your local Cooperative
Extension office or state Department of Agriculture and Markets
to obtain copies of the regulations for labeling maple products.
can I best market maple products?
Individual producers have come up with many creative ways to market
maple products. Visit local producers, farmers markets, grocery
stores, and the Internet to get ideas.
causes syrup to have a musty or moldy flavor or smell?
Syrup that is improperly packed will mold, sour, or ferment. Syrup
must be packed at 180oF and at a minimum of 66 Brix to
are the "rock" crystals sometimes found in the bottom
of a syrup container?
Sugar crystals will precipitate from syrup that has too high a density
(over 67 Brix).
all containers need to be labeled showing who produced the syrup
if they are sold in a store?
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 x 6 feet) may boil 25 gallons per hour and a
large evaporator (6 feet x 18 feet) 380 gallons per hour.
long does the sugaring season usually last?
The length of the sap season varies depending on the temperature.
An average sap season is about six weeks.
it cost effective to produce value-added products like cream and
Yes, if produced in sufficient quantities and marketed to achieve
syrup be reheated once it has been containerized?
Syrup is reheated when it is removed from bulk containers for packaging
into retail containers. If a consumer finds bacteria, mold, or yeast
growth on syrup he or she has purchased, he or she should remove
the visible growth and reheat the syrup to a minimum of 180oF
(do not boil), skim any visible growth, filter, and repackage the
syrup. If syrup still has an off-flavor, it should be discarded.
Also, the sugar content may increase causing sugar crystals to form.
does a producer determine when he or she should upgrade equipment
or increase the size of the operation?
When markets outstrip production or when current production requires
long work hours. Larger or more efficient equipment can reduce the
hours and fuel required to produce syrup.
is maple syrup different colors?
The color in maple syrup results from a browning reaction that occurs
during the latter stages of evaporation. Sap that is boiled longer
makes a darker colored syrup. Therefore, anything that slows the
evaporation process, such as uneven or weak fire, an inefficient
evaporator, or too much sap in the evaporator, will cause dark syrup.
Because color develops during the latter stages of boiling sap,
it is particularly important to reduce processing time as the sap
approaches syrup. Microorganisms in sap can also cause darkening.
Sap flowing into the sap house can be treated with UV light to kill
the microorganisms. Sap should be processed as soon as possible
after collection to reduce the potential for microorganisms and
thus reduce the quality of syrup produced.
Syrup may also darken during storage. To prevent darkening, hot
syrup that has just been put into containers should be allowed to
cool before the containers are packed close together. Gas exchange
during storage can also cause syrup to darken.