Everything You Ever Wanted To Know
About Maple Syrup
A History of Maple Syrup
Before the arrival of European settlers in 1608, the custom of collecting and boiling the sap of sugar maples had long been practiced by First Nations peoples of eastern North America. Each spring, Native communities moved from their winter hunting grounds into the sugar bush. There, they made v-shaped incisions in the bark of sugar maples with stone tools, fixed hand-carved, concave pieces of bark or reeds to the incisions, and leaned woven birch baskets against the trees to collect the flowing sap.
Native peoples originally used sap as cooking liquid for stews and for curing meats, but over time they began processing the sap into syrup. In the beginning, they would heat stones in a fire and then drop them into sap-filled vats made of moose hide or bark to evaporate the water content – a very slow and painstaking process. Later, they boiled sap in brass kettles placed over a fire.
Maple syrup became a valuable trading commodity when people discovered a method for transforming syrup into sugar through straining, reheating, thickening, and stirring. They would pack the granulated sugar into birch bark cones, tie them together and hang them from ceilings for storage. They also transformed the syrup into maple candy by pouring it into wooden molds or directly into the snow and leaving it to harden.
Canada's early European settlers learned the skills of tapping trees and making syrup from these Native communities. Over time, methods evolved: instead of making v-shaped cuts in the bark, settlers manually drilled holes into trees and pushed wooden spouts into them. They hung buckets from nails below the spouts to protect the sap from strong winds or animals, and used iron pots over open fires to concentrate the sap.
The Sugar Bush
The temperate deciduous forest of eastern North America is home to a rich array of life, including dozens of species of mammals, birds, insects, reptiles, amphibians, and invertebrates. Over 100 species of trees grow here, three quarters of which are deciduous. These eastern forests are considered one of the most important biomes on our planet.
Within this diverse range lies the northern hardwood forest, a swath of beautiful woods stretching from the midwestern United States through Ontario, Québec, New England and into the Maritimes. The northern hardwood forest is dominated by yellow birch (Betula alleghaniensis), American beech (Fagus grandifolia), and sugar maple (Acer saccharum). Two conifers – eastern hemlock (Tsuga canadensis) and white pine (Pinus strobus) – also grow abundantly among the broad-leaved species.
Here, the world's maple syrup is produced – and a great majority of it right here in Québec. The syrup is made in hardwood forests that are managed to varying degrees with the intention of promoting the dominance of sugar maples. This involves cutting down sick trees and selectively thinning to encourage growth, a process that would occur naturally over dozens if not hundreds of years. Skillful management speeds up time in the forest by allowing it to mature at a faster rate, but it can still take generations to bring an individual tree into production.
Sustainable practices are critical to supporting healthy forests and the long-term production of maple syrup. They include maintaining a healthy degree of biodiversity; avoiding the use of heavy, soil-compacting equipment; and cutting only when trees are dormant and the ground is frozen to avoid damaging the forest floor, the bark of neighbouring trees, or nesting birds and other wildlife.
Within the sugar bush, environmental conditions, soil types and exposure to sunlight all affect the trees' production of sap. Trees growing with adequate moisture and nutrients will produce more sap than trees growing in infertile soil or dry conditions, as will trees that are exposed to more sun and therefore capable of increased photosynthesis. Those that have suffered defoliation from insects or loss of branches will naturally produce less sap that healthy trees.¹
¹Kozlowski T, Pallardy S (editors). Physiology of Woody Plants. San Diego: Academic Press; 1997.
The Maple Tree
As temperatures rise in the spring, activity in the cells of a maple tree's cambium produces carbon dioxide. This carbon dioxide, when released into the intercellular spaces in the cambium, pressurizes the "chamber". Osmotic pressure from the presence of sugar and other substances dissolved in the sap also contributes to this positive pressure, causing sap to flow out through a tap hole.
During cooler periods when temperatures fall below freezing, the carbon dioxide cools and contracts. Negative pressure develops, drawing water into the tree from its roots and replenishing its sap. This allows it to flow again during the next warm period. Incredibly, these pressures can range from –10 psi to 40 psi (–68 kpa to 275 kpa). As long as a pattern of freeze and thaw continues, the production of maple syrup goes on uninterrupted; if it becomes too warm or too cold, however, production quickly drops.
The sap of sugar maples contains a higher concentration of sugar that the sap of other trees. This sugar is the product of the photosynthesis that occurred during the previous summer. The trees store the carbohydrates produced by photosynthesis in the form of starch. Starch is converted to sucrose (sugar) and dissolves in sap. Amino acids in the sap give maple syrup its distinctive flavour, which differs from that of pure sugar.
A single tap in one sugar maple tree can produce 30–60 litres of sap annually. At an average water to sugar ratio of 40:1, this will yield 0.75–1.5 litres of pure maple syrup.
Maple Sap Harvesting
Tapping the Trees
Each year, the same sugar maples are tapped for sap. A small hole is drilled through the bark and into the cambium, typically in late January or early February. This allows sap to flow freely into the hole and out through the tap installed there. Damage to the tree is minimal, and a healthy tree will completely close this hole in a single growing season. Less healthy trees may take longer to recover; this is dangerous primarily because the hole functions as an entry point for the most serious threat to trees in any forest – fungus.
Lines vs. Buckets
In the majority of sugar bushes, thin tubes suspended from the trees weave their way throughout the forest. These lines collect the sap that trickles out through the taps described above. All the lines of the forest lead back to the sugar camp, where the sap is processed.
Before lines were used, sap was collected in buckets hung from hooks at every tree. As the buckets filled with sap, gatherers would carry larger pails, often on snowshoes, from tree to tree collecting the sap from the buckets. The sap was then transported in a larger reservoir pulled by tractor or horse. Though some small producers still use a traditional bucket system, the arguments for using lines are compelling: old buckets can leach lead into the sap, spoil sap more rapidly in warm weather, and have flows that aren't worth emptying for several days. Bucket systems also require all-weather road systems in the sugarbush, which can damage the forest floor.
The large reservoirs where sap is collected and stored before being transformed into syrup need to be cleaned on a regular basis. As temperatures warm in the spring, bacteria accumulate in the sap and on the equipment. Daily cleaning is required to prevent the production of poor-quality or spoiled syrup.
Click to enlarge:
Syrup Production Process
From Sap to Sugar
Fresh sap flowing out of the maple tree contains anywhere from 1% to 6% sugar. After the process of evaporation, maple syrup is 66–67% sugar. This transformation involves the removal of water, but also the caramelization of sugars. The process of evaporation is carried out by boiling the sap until its sugar reaches the correct concentration. Too little and the syrup can referment; too much and it may crystallize. It can take as many as 40 litres of sap to produce 1 litre of syrup.
Sap is generally concentrated in one of two ways. Traditionally, sap was boiled for many hours until it achieved the right concentration. Large pans called arches were once exclusively fired with wood; newer arches are fired with oil, electricity, or pelletized wood, though wood-fired arches still exist. The arches are designed to allow sap (or concentrated sap) to flow slowly into the pan while thicker, partially evaporated sap flows towards the front. From here the concentrated sap flows into a finishing pan fired at a lower teperature for the delicate and sometimes precarious final stages of syrup production.
Modern technologies have also been applied to the production of syrup. One technology that offers enormous cost and energy savings is the reverse osmosis system. Using pressure, this system forces sap through a membrane that is only permeable to water, thereby increasing the sugar content of the remaining sap and concentrating its other components. The resulting concentrate must still be processed in a heated evaporator to obtain the characteristic maple flavour by caramelizing the sugars. Reverse osmosis will concentrate sap originally at 2% sugar to between 8% and 16% sugar, and remove half of the initial water. A recent development in osmosis technology can now concentrate sugars to 35%.
The sugar in maple sap is almost entirely polysacharide sucrose. When heat is applied in the evaporation process, this sucrose is broken down into the monosacharides glucose and fructose, which caramelize at a lower temperature. The caramelization of these sugars, as well as the contribution of flavour development during the Maillard reaction, changes the flavours of the syrup as it concentrates. These are are all non-enzymatic changes.
Once maple syrup is produced, it must be filtered. Failure to undertake this final step will yield a poor-quality, bitter, and sandy syrup. The industry standard for filtration has become the filterpress; diatomaceous earth is added to the hot syrup prior to filtration, and then the syrup is pumped through a series of cast plates with filter paper. As the syrup passes through the paper, the diatomaceous earth builds up to create a filtration matrix that removes the insoluble solids from the syrup. These insoluble solids, commonly referred to as sugar sand, are mostly the concentrated minerals naturally found in sap. Consisting largely of calcium, potassium, magnesium, manganese, and zinc, the sugar sand is inedible but harmless – and very good for your garden in calculated doses!
Maple Syrup Dissected
Maple sap contains sucrose and trace amounts of oligosaccharides, including raffinose. Sucrose concentration is typically 2–3%, though it can range from 0.5–10%. Other organic compounds in the sap include organic acids, amino acids, amides, ammonia, and peptides. The organic acids in the sap include malic (0.21%), citric (0.002%), and traces of succinic, fumaric and several others. The total mineral content of the sap is 0.66%. Common minerals include potassium (0.26%), calcium (0.07%), silicon oxide (0.02%) and lesser amounts of manganese, sodium, and magnesium.¹
¹Willits, CO. Maple Syrup Producers Manual. Washington: US Department of Agriculture; 1958.
Grades, Quality & Flavour
Understanding Maple Syrup Grades
When you pick up a bottle of maple syrup off the shelf, the only information that will give you any idea of what that syrup will taste like is the grade. The grading of maple syrup has changed significantly over the past decades, and while experts have established internationally agreed-upon grades, the old grading system persists on bottles and in the minds of some consumers.
Unfortunately, the grading system makes no effort to enlighten people on the array of flavours and faults that can be found in maple syrup. Independent grading agencies will test syrup and reprimand producers for syrup that contains a fault, but nothing stops the packers who bottle the majority of the world's maple syrup from using a percentage of faulted syrup in their generic blends.
The following is an attempt to describe the grades, flavours and faults found in maple syrup. We hope it helps you to understand the range of maple syrup's qualities and characteristics, and encourages you to appreciate its many subtleties.
Determining Light Transmission in Maple Syrup
To measure light transmission in maple syrup, we use a spectrophotometer with matched square optical cells that have a 10mm light path at a wavelength of 560nm – the wavelength of yellows. It expresses colour values in percentage of light transmission. Using a wavelength visible to the human eye, we determine what percent of light being shone at a vial of maple syrup is able to pass through it. The darker the syrup, the lower the percentage of light transmitted. The lighter the syrup, the higher the percentage.
The old grading system uses light transmission to characterize syrups according to the following categories. The grades, listed below, account for class, colour, and percentage.
1. AA, Extra Light: 75% or more
2. A, Light: 60.5% or more but less than 75%
3. B, Medium: 44% or more but less than 60.5%
4. C, Amber: 27% or more but less than 44%
5. D, Dark: less than 27%
The new grading system also uses light transmission to categorize syrups, but within wider ranges. This makes sense, considering syrup can naturally darken over time. The grades, listed below, account for colour, taste, and percentage.
1. Golden, Delicate Taste (Doré, goût délicat) no less than 75.0%
2. Amber, Rich Taste (Ambré, goût riche) less than 75.0 but no less than 50.0%
3. Dark, Robust Taste (Foncé, goût robuste) less than 50.0 but no less than 25.0%
4. Very Dark, Strong Taste (Très foncé, goût prononcé) less than 25.0%
In addition to measuring light transmission, producers must bottle maple syrup at a specific density of 66 degrees brix or greater (if the syrup is concentrated too much, however, it can crystallize).
Maple Syrup Flavours
There's a science to tasting maple syrup. Specially trained practitioners (known as sensory evaluators) from Agriculture & Agri-Food Canada (AAFC) and maple product scientists from Centre ACER have developed tools to explore the range of maple flavours and characterize the taste and smell sensations that maple syrup produces.
Their Flavour Wheel of Maple Products (below) was developed from a list of approximately 250 reference characteristics provided by several tasting panels. It provides a scientific basis for objective, reliable descriptions of the many tastes of maple syrup. Like a dictionary, it establishes a common language for producers to discuss and describe complex flavours in detail and with a high degree of accuracy.
Maple Syrup Faults
As previously mentioned, colour and grade only tell part of any maple syrup's story. Yet, unless one or more serious faults is identified prior to bottling, additional factors of taste and quality are not communicated to those who are buying the syrup. Understanding potential faults in maple syrup and why they occur is critical for maple syrup producers, but we think it's also important for discerning consumers!
The following determinable faults were published by the Cornell University Maple Program.
Musty: this off-flavour can become present when hot syrup is run through filters that contain mold, or when syrup is stored in poorly sealed containers. It tastes yeasty or moldy, and usually has a moldy odour.
Ferment: fermented syrup will have a sickeningly sweet flavour that, depending on the type of ferment, may be honey-like, alcoholic or fruity to the taste. Severe ferment may create a foamy appearance. Ferment usually develops from one of two problems: 1) if syrup has not been concentrated to the correct amount of sugar, yeast can begin fermenting sugars into alcohol; or 2) if syrup is stored in improperly cleaned barrels, fermentation can occur even in syrup with the correct density. Even steam-cleaned barrels can retain enough moisture to foster yeast, mold, and bacteria in great numbers.
Sour sap: as the weather warms near the end of the sugaring season, any sap left in a tank begins to warm and spoil. Syrup made from this sap has a stringy appearance when poured, and the flavour is very sour.
Burnt niter: when sap is boiled, minerals precipitate out to form niter. This niter collects in the compartment in the front pan where the syrup is drawn off and, if left to build up, can rise up and burn the syrup. This creates a combination off-flavour: a burned taste and a niter taste with a slightly fizzy effect. This can be prevented by switching draw-off sides frequently, or changing front pans.
Scorch: this off-flavour creates a burned taste, caused when low levels of syrup in the front pans are burned in the evaporators.
Earthy flavour: tapping into punky wood, cracked wood, or dark-coloured/stained areas in a tree produces syrup with this off-flavour, which tastes and smells like garden soil. Careful tapping can prevent this fault.
Metabolism: this off-flavour is attributed to changes in the metabolism of trees when temperatures warm, which can occur at any time in the sugaring season. A metabolism off-flavour robs the syrup of most of its maple flavour, leaving a taste likened to wood, peanut butter, or popcorn. A cardboard-like flavour or chocolatey smell may also be present.
Buddy: buddy syrup is usually produced during the late season, depending on weather conditions. When trees begins to produce buds, their sap takes on a distinctive quality that is then transferred into the syrup. Buddy syrup usually tastes chocolatey, almost like a tootsie roll. If very strong, it may taste slightly bitter.
Other Maple Products
Granulated maple sugar is the most common and versatile product made from maple syrup. Because it has no available water, it is shelf-stable and will never separate or mold. It can be stored indefinitely at room temperature and, with proper packaging and moisture control, it won't loose its granular nature. It can be reconstituted into maple syrup of any density and from there converted into any of the other maple confections as well. Because of this storability and versatility, chefs and bakers find maple sugar very easy to use. Maple sugar can replace brown or white sugar in recipes on a one-to-one basis by volume or by weight. It enhances the flavour of baking and savoury dishes and is valued by many people for its natural, sustainable origin. By the way, Cosman & Webb organic maple sugar can be purchased online here.
Maple butter, also referred to as maple cream or maple spread, may sound like it contains dairy products, but in fact it's made from 100% pure maple syrup. The technique involves additional concentration and evaporation, quick cooling, stirring, and finally packaging at room temperature. Maple butter is light in colour with a smooth, creamy texture, and can be used on toast, bagels, muffins, pancakes, or in combination with other baked goods and sweets. Maple butter is an all-natural product comprised mainly of sugars, but, like maple syrup, it has other important nutrients such as amino acids, proteins, organic acids, minerals (calcium and potassium being the most prevalent) and trace levels of some vitamins. Maple butter should be kept in the freezer for long-term storage, and in the fridge after opening in order to prevent separation.
Maple candy is made by boiling sap past the point of becoming maple syrup, but not so long as to become maple butter or maple sugar. When the syrup reaches a temperature of approximately 112 °C (234 °F) – at which point it shouldn't be stirred or it will form grainy crystals (that is, maple sugar) – it is poured into molds or directly onto clean snow, where the cold causes it to quickly harden. Once sufficiently hardened, the candy can be popped out of the molds or picked up off the snow with a wooden stick and eaten. The higher the temperature at which the initial syrup is boiled, the harder the candy will be. A low-temperature boil will produce something more like soft maple taffy.
Maple water, also known as maple sap, is a more locavore-friendly beverage than its competitor, coconut water. Maple water contains a small amount of naturally occurring sugar – 4 grams per 8.5 ounces (approximately half as much as coconut water) – and trace minerals, including calcium, potassium, manganese, and magnesium. Maple water is only available for a short period of time each year, and doesn't stay fresh for very long. Several years of work were put into finding a way to sterilize and preserve maple water for a shelf life of at least one year, and now it is most often pasteurized before packaging. People enjoy maple water as a hydrating drink after exercising and playing sports, but it can be used in many different ways: as coffee or tea water, in cocktails to add a hint of sweetness and maple essence, or in cooking water to give depth and subtle flavour.
Canada’s maple syrup-producing regions include Québec, Ontario, New Brunswick, Prince Edward Island and Nova Scotia. According to 2014 statistics, Canada produces 80% of the world’s pure maple syrup; of that 80%, Québec produces 72%. Of the approximate 8600 maple syrup businesses in Canada, the Federation of Québec Maple Syrup Producers (FPAQ) governs 7400. Canadian maple syrup is exported to approximately 50 countries, including the United States, the primary importer.
The health benefits of maple syrup are attributed to the presence of various vitamins and minerals. For example, a quarter-cup of maple syrup contains 100% of the recommended daily value of manganese, which improves energy production and is necessary for normal brain and nerve function. It also provides 37% of the daily value of riboflavin, which aids in metabolic process, and 18% of the daily value of zinc, which is essential for a healthy immune system. Other minerals found in maple syrup are magnesium, calcium, and potassium, which help to decrease the risk of hypertension and stroke.
Health Canada provides nutritional value information for pure maple syrup as well as other common sweeteners, including honey, white sugar, brown sugar, and agave syrup (below) .
Nutrition Value Comparison Chart
Health Canada also provides information on calories and sugars in maple syrup compared to other sweeteners (below).
Sugar & Calorie Comparison Chart
Finally – to further our case for the health benefits of maple syrup – according to recent studies:
- pure maple syrup does not cause the same spike in insulin levels as some other sugars do; and
- pure maple syrup has the same beneficial classes of polyphenlolic compounds that are found in berries, tomatoes, tea, red wine, whole wheat, and flax seed.
Organic vs. Non-Organic
All maple sap is unadulterated and pure – it comes directly from nature without any human intervention or chemical processes. So why would a maple syrup producer feel that organic certification is important? Organic certification guarantees good, clean practices from sapling to syrup. To us, this reflects our ecological and social values, and it also speaks to our love and respect for the forests where we live.
Certified organic maple syrup is made according to specific guidelines and regulations that cover forest management, processing, and storage to ensure that no chemicals or other inorganic products are used at any point in production. The extra work that this entails, and the certification fee, leads to the higher cost of certified organic maple syrup.
The following restrictions and guidelines apply for certified organic maple syrup producers.
- We must keep production plans, production records, sales records, inventory records, product traceability, and site maps on file for both the FPAQ (if in Québec) and our organic certifier.
- We must have buffers surrounding our maple bush if it is situated beside farmland (for example, Christmas tree lots) that use non-organic products such as pesticides.
- We must ensure that at least 15% of the trees in our sugar bush are not sugar maples in order to maintain forest diversity. The undergrowth in our forests may not be cut, and fertilizer use is limited to wood ash, lime, or other approved organic fertilizers.
- We must not use poison as a form of animal control. Large and small animals can damage sap lines for a number of different reasons, at Cosman & Webb Townships Organic we accept and repair all damage, and no harm comes to any animal.
- We must install protectors on our lines for collecting maple sap (if applicable) to avoid damaging the maple trees.
- We must ensure our maple trees have a diameter of at least 20cm to be tapped once; at least 40 cm to be tapped twice; and at least 60cm to be tapped a maximum of three times in one season. *New research shows that installing more than one tap per tree in a season doubles the tree's scar tissue while resulting in only about 30% more sap. For the long-term health and sustainability of the forest, we have decided to install a single tap per tree per season, no matter what the size of the tree.
- We must use only food-grade ethyl as a disinfectant for cleaning tap holes (to ensure there is no bacteria in the tap hole when the tree is tapped). *Non-organic maple syrup producers can use any variety of chemicals as disinfectants during the maple season.
- We must ensure that no mineral components of sap are removed during the reverse osmosis process.
- We must only use stainless steel pans, and only certified organic oils as de-foamers. During the boiling season, we can only use water for cleaning these pans, and vinegar or fermented sap for cleaning at the end of the season.
Cosman & Webb maple syrup and maple sugar is certified organic through