Maple syrup is a syrup usually made from the xylem sap of sugar maple, red maple, or black maple trees, although it can also be made from other maple species such as the bigleaf maple. In cold climates, these trees store starch in their trunks and roots before the winter; the starch is then converted to sugar that rises in the sap in the spring. Maple trees can be tapped by boring holes into their trunks and collecting the exuded sap. The sap is processed by heating to evaporate much of the water, leaving the concentrated syrup.
Maple syrup was first collected and used by aboriginal people of North America. The practice was adopted by European settlers, who gradually improved production methods. Technological improvements in the 1970s further refined syrup processing. The Canadian province of Quebec is by far the largest producer, responsible for about three-quarters of the world's output; Canada exports more than C$145 million (approximately US$141 million) worth of maple syrup per year. Vermont is the largest producer in the United States, generating about 5.5 percent of the global supply.
Maple syrup is graded according to the Canada, United States, or Vermont scales based on its density and translucency. Sucrose is the most prevalent sugar in maple syrup. In Canada, syrups must be at least 66 percent sugar and be made exclusively from maple sap[1] to qualify as maple syrup. In the United States, a syrup must be made almost entirely from maple sap to be labelled as "maple".
Maple syrup is often eaten with pancakes, waffles, French toast, or oatmeal and porridge. It is also used as an ingredient in baking, and as a sweetener and flavouring agent. Culinary experts have praised its unique flavour, although the chemistry responsible is not fully understood.
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Three species of maple trees are predominantly used to produce maple syrup and related products: the sugar maple (Acer saccharum), the black maple (A. nigrum), and the red maple (A. rubrum),[2] because of the high sugar content (roughly two to five percent) in the sap of these species.[3] The black maple is included as a subspecies or variety in a more broadly viewed concept of A. saccharum, the sugar maple, by some botanists.[4] Of these, the red maple has a shorter season because it buds earlier than sugar and black maples, which alters the flavour of the sap.[5]
A few other (but not all) species of maple (Acer) are also sometimes used as sources of sap for producing maple syrup, including the box elder or Manitoba maple (Acer negundo),[6] the silver maple (A. sacharinum),[7] and the bigleaf maple (A. macrophyllum).[8] A syrup similar to maple syrup can also be produced from the sap of certain species of birch (Betula).[9]
Aboriginal peoples living in the northeastern part of North America were the first groups known to have produced maple syrup and maple sugar. According to aboriginal oral traditions, as well as archaeological evidence, maple tree sap was being processed into syrup long before Europeans arrived in the region.[10][11] There are no authenticated accounts of how maple syrup production and consumption began,[12] but various legends exist; one of the most popular involves maple sap being used in place of water to cook venison served to a chief.[11] Other stories credit the development of maple syrup production to Nanabozho, Glooskap, or the squirrel. Aboriginal tribes developed rituals around sugar-making, celebrating the Sugar Moon (the first full moon of spring) with a Maple Dance.[13] Many aboriginal dishes replaced the salt traditional in European cuisine with maple sugar or syrup.[11]
The Algonquians recognized maple sap as a source of energy and nutrition. At the beginning of the spring thaw, they used stone tools to make V-shaped incisions in tree trunks; they then inserted reeds or concave pieces of bark to run the sap into buckets, which were often made from birch bark.[12] The maple sap was concentrated either by dropping hot cooking stones into the buckets[14] or by leaving them exposed to the cold temperatures overnight and disposing of the layer of ice that formed on top. Production of maple syrup is one of only a few agricultural processes in North America that is not a European colonial import.[12]
In the early stages of European colonization in northeastern North America, native peoples showed the arriving colonists how to tap the trunks of certain types of maples during the spring thaw to harvest the sap.[15] André Thevet, the "Royal Cosmographer of France", wrote about Jacques Cartier drinking maple sap during his Canadian voyages.[16] By 1680, European settlers and fur traders were involved in harvesting maple products.[17] However, rather than making incisions in the bark as the natives did, the Europeans opted to use the less destructive method of drilling tapholes in the trunks with augers. During the 17th and 18th centuries, processed maple sap was used primarily as a source of concentrated sugar, in both liquid and crystallized-solid form, as cane sugar had to be imported from the West Indies.[12][13]
Maple sugaring parties typically began to operate at the start of the spring thaw in regions of woodland with sufficiently large numbers of maples.[15] Syrup makers first bored holes in the trunks, usually more than one hole per large tree; they then inserted wooden spouts into the holes and hung a wooden bucket from the protruding end of each spout to collect the sap. The buckets were commonly made by cutting cylindrical segments from a large tree trunk and then hollowing out each segment's core from one end of the cylinder, creating a seamless, watertight container.[12] Sap filled the buckets, and was then either transferred to larger holding vessels (barrels, large pots, or hollowed-out wooden logs), often mounted on sledges or wagons pulled by draft animals, or carried in buckets or other convenient containers.[18] The sap-collection buckets were returned to the spouts mounted on the trees, and the process was repeated for as long as the flow of sap remained "sweet". The specific weather conditions of the thaw period were, and still are, critical in determining the length of the sugaring season.[19] As the weather continues to warm, a maple tree's normal early spring biological process eventually alters the taste of the sap, making it unpalatable, perhaps due to an increase in amino acids.[7]
The boiling process was time-consuming. The harvested sap was transported back to the party's base camp, where it was then poured into large vessels (usually made from metal) and boiled to achieve the desired consistency.[12] The sap was usually transported using large barrels pulled by horses or oxen to a central collection point, where it was processed either over a fire built out in the open or inside a shelter built for that purpose (the "sugar shack").[12][20]
Around the time of the American Civil War, syrup makers started using large, flat sheet metal pans as they were more efficient for boiling than heavy, rounded iron kettles, because of a greater surface area for evaporation.[20] Around this time, cane sugar replaced maple sugar as the dominant sweetener in the US; as a result, producers focused marketing efforts on maple syrup. The first evaporator, used to heat and concentrate sap, was patented in 1858. In 1872, an evaporator was developed that featured two pans and a metal arch or firebox, which greatly decreased boiling time.[12] Around 1900, producers bent the tin that formed the bottom of a pan into a series of flues, which increased the heated surface area of the pan and again decreased boiling time. Some producers also added a finishing pan, a separate batch evaporator, as a final stage in the evaporation process.[20]
Buckets began to be replaced with plastic bags, which allowed people to see at a distance how much sap had been collected. Syrup producers also began using tractors to haul vats of sap from the trees being tapped (the sugarbush) to the evaporator. Some producers adopted motor-powered tappers and metal tubing systems to convey sap from the tree to a central collection container, but these techniques were not widely used.[12] Heating methods also diversified: modern producers use wood, oil, natural gas, propane, or steam to evaporate sap.[20] Modern filtration methods were perfected to prevent contamination of the syrup.[21]
A large number of technological changes took place during the 1970s. Plastic tubing systems that had been experimental since the early part of the century were perfected, and the sap came directly from the tree to the evaporator house.[22] Vacuum pumps were added to the tubing systems, and preheaters were developed to recycle heat lost in the steam. Producers developed reverse-osmosis machines to take a portion of water out of the sap before it was boiled, increasing processing efficiency.[12]
Improvements in tubing and vacuum pumps, new filtering techniques, "supercharged" preheaters, and better storage containers have since been developed. Research continues on pest control and improved woodlot management.[12] In 2009, researchers at the University of Vermont unveiled a new type of tap that prevents backflow of sap into the tree, reducing bacterial contamination and preventing the tree from attempting to heal the bore hole.[23]
Production methods have been streamlined since colonial days, yet remain basically unchanged. Sap must first be collected and boiled down to obtain pure syrup without chemical agents or preservatives. Maple syrup is made by boiling between 20 and 50 litres (5.3 and 13 US gal) of sap (depending on its concentration) over an open fire until 1 litre (0.26 US gal) of syrup is obtained, usually at a temperature 4.1 °C (7.4 °F) over the boiling point of water.[20][24] Syrup can be boiled entirely over one heat source or can be drawn off into smaller batches and boiled at a more controlled temperature.[25]
The finished syrup has a density of 66° or greater on the Brix scale (a hydrometric scale used to measure sugar solutions).[26] The syrup is then filtered to remove sugar sand, crystals made up largely of sugar and calcium malate.[27] These crystals are not toxic, but create a "gritty" texture in the syrup if not filtered out.[28] The filtered syrup is graded and packaged while still hot, usually at a temperature of 82 °C (180 °F) or greater. The containers are turned over after being sealed to sterilize the cap with the hot syrup. Packages can be made of metal, glass, or coated plastic, depending on volume and target market.[29] The syrup can also be heated longer and further processed to create a variety of other maple products, including maple sugar, maple butter or cream, and maple candy or taffy.[30]
Off-flavours can sometimes develop during the production of maple syrup; causes include contaminants in the boiling apparatus, such as paint or cleanser; changes in the sap, such as fermentation when it has been left sitting too long; and changes in the tree, such as "buddy sap" late in the season when budding has begun.[31] In some circumstances it is possible to remove off-flavours through processing.[32]
Maple syrup production is centred in northeastern North America; however, given the correct weather conditions, it can be made wherever suitable species of maple trees grow.
A maple syrup production farm is called a "sugarbush" or "sugarwood". Sap is often boiled in a "sugar house" (also known as a "sugar shack," "sugar shanty," or cabane à sucre), a building louvered at the top to vent the steam from the boiling sap.[33]
Maples are usually tapped beginning at 30 to 40 years of age. Each tree can support between one and three taps, depending on its trunk diameter. The average maple tree will produce 35 to 50 litres (9.2 to 13 US gal) of sap per season, up to 12 litres (3.2 US gal) per day.[34] This is roughly equal to 7% of its total sap. Seasons last for four to eight weeks, depending on the weather.[35] During the day, starch stored in the roots for the winter rises through the trunk as sugary sap, allowing it to be tapped.[19] Sap is not tapped at night because the temperature drop inhibits sap flow, although taps are typically left in place overnight.[36] Some producers also tap in autumn, though this practice is less common than spring tapping. Maples can continue to be tapped for sap until they are over 100 years old.[34]
Canada produces more than 80 percent of the world's maple syrup, producing about 26,500,000 litres (7,000,000 US gal) in 2004. The vast majority of this comes from the province of Quebec, which is the world's largest producer, with about 75 percent of global production totalling 24,660,000 litres (6,510,000 US gal) in 2005.[37] As of 2003, Quebec had more than 7,000 producers, collectively making over 24,000,000 litres (6,300,000 US gal) of syrup.[38] Production in Quebec is controlled through a supply management system, with producers receiving quota allotments from the Fédération des producteurs acéricoles du Québec, which also maintains reserves of syrup.[39] Canada exports more than 9,400,000 litres (2,500,000 US gal) of maple syrup per year, valued at more than C$145 million.[22][40] The provinces of Ontario, Nova Scotia, New Brunswick, and Prince Edward Island produce smaller amounts of syrup.[37]
The Canadian provinces of Manitoba and Saskatchewan produce maple syrup using the sap of the box elder or Manitoba maple (Acer negundo).[41] However, a Manitoba maple tree's yield is usually less than half that of a similar sugar maple tree.[42] Manitoba maple syrup has a slightly different flavour from sugar-maple syrup, because it contains less sugar and the tree's sap flows more slowly.
Vermont is the biggest US producer, with over 1,140,000 US gallons (4,300,000 l) during the 2011 season, followed by New York with 564,000 US gallons (2,130,000 l) and Maine with 360,000 US gallons (1,400,000 l). Wisconsin, Ohio, New Hampshire, Michigan, Pennsylvania, Massachusetts, and Connecticut all produced marketable quantities of maple syrup of less than 120,000 US gallons (450,000 l) each in 2011.[43] As of 2003, Vermont produced about 5.5 percent of the global syrup supply.[38]
Maple syrup has been produced on a small scale in some other countries, notably Japan and South Korea.[44] However, in South Korea in particular, it is traditional to consume maple sap, called gorosoe, instead of processing it into syrup.[45] Japan is a large importer of maple syrup: in 2010, 10.1 percent of Canada's maple syrup exports (a value of C$28 million) went to Japan.[46]
In Canada, maple syrup is classified as one of three grades, each with several colour classes. These include Canada #1, including Extra Light (sometimes known as AA), Light (A), and Medium (B); #2 Amber (C); and finally #3 Dark (D).[47] In addition, Canada #2 Amber may be labelled "Ontario Amber" when produced and sold in that province only.[48] A typical year's yield for a maple syrup producer will be about 25 to 30% of each of the #1 colours, 10% #2 Amber, and 2% #3 Dark.[26]
The United States uses different grading standards. Maple syrup is divided into two major grades: Grade A and Grade B. Grade A is further divided into three subgrades: Light Amber (sometimes known as Fancy), Medium Amber, and Dark Amber. The Vermont Agency of Agriculture Food and Markets uses a similar grading system of colour, and is roughly equivalent, especially for lighter syrups.[47] The Vermont grading system differs from the US system in maintaining a slightly higher standard of product density (measured on the Baumé scale). New Hampshire maintains a similar standard, but not a separate state grading scale. The Vermont-graded product has 0.9% more sugar and less water in its composition than US-graded. A grade of syrup not for table use, called commercial or Grade C, is also produced under the Vermont system.[49] Vermont inspectors enforce strict syrup grading regulations, and can fine producers up to US$1000 for labelling syrup incorrectly.[50]
Extra Light and Grade A typically have a milder flavour than Grade B, which is very dark, with a rich maple flavour.[49] The dark grades of syrup are used primarily for cooking and baking, although some specialty dark syrups are produced for table use.[51] The classification of maple syrup in the US depends ultimately on its translucence. US Grade A Light Amber has to be more than 75% translucent, US Grade A Medium Amber has to be 60.5 to 74.9% translucent, US Grade A Dark Amber has to be 44.0 to 60.4% translucent, and US Grade B is any product less than 44.0% translucent.[21]
| Nutritional value per 100 g (3.5 oz) | |
|---|---|
| Energy | 1,093 kJ (261 kcal) |
| Carbohydrates | 67.09 g |
| - Sugars | 59.53 g |
| - Dietary fiber | 0 g |
| Fat | 0.20 g |
| Protein | 0 g |
| Thiamine (vit. B1) | 0.006 mg (1%) |
| Riboflavin (vit. B2) | 0.01 mg (1%) |
| Niacin (vit. B3) | 0.03 mg (0%) |
| Pantothenic acid (B5) | 0.036 mg (1%) |
| Vitamin B6 | 0.002 mg (0%) |
| Calcium | 67 mg (7%) |
| Iron | 1.20 mg (9%) |
| Magnesium | 14 mg (4%) |
| Manganese | 3.298 mg (157%) |
| Phosphorus | 2 mg (0%) |
| Potassium | 204 mg (4%) |
| Zinc | 4.16 mg (44%) |
| Percentages are relative to US recommendations for adults. Source: USDA Nutrient Database |
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The basic ingredient in maple syrup is the sap from the xylem of sugar maple or various other species of maple trees. It consists primarily of sucrose and water, with small amounts of other sugars such as fructose and glucose. Organic acids, the most notable one being malic acid, make the syrup slightly acidic. Maple syrup has a relatively low mineral content, consisting largely of potassium and calcium, but also contains nutritionally significant amounts of zinc and manganese. Maple syrup also contains trace amounts of amino acids, which may contribute to the "buddy" flavour of syrup produced late in the season, as the amino acid content of sap increases at this time.[52] Additionally, maple syrup contains a wide variety of volatile organic compounds, including vanillin, hydroxybutanone, and propionaldehyde. It is not yet known exactly which compounds are primarily responsible for maple syrup's distinctive flavour.[27]
Maple syrup is similar to sugar with respect to calorie content, but is a source of manganese, with 13 grams containing about 0.44 milligrams or 22 percent of the US Food and Drug Administration Daily Value (DV%) of 2 milligrams.[53] It is also a source of zinc with 13 grams containing 0.55 milligrams or 3.7 percent of the DV% of 15 milligrams.[53][54] Compared to honey, maple syrup has 15 times more calcium and 1/10 as much sodium.[36]
Scientists have found that maple syrup's natural phenols – potentially beneficial antioxidant compounds – inhibit two carbohydrate-hydrolyzing enzymes that are relevant to type 2 diabetes. In the study, 34 new compounds were discovered in pure maple syrup, five of which have never before been seen in nature. Among the five new compounds is quebecol, a phenolic compound created when the maple sap is boiled to create syrup.[55]
British culinary expert Delia Smith described maple syrup as "a unique ingredient, smooth- and silky-textured, with a sweet, distinctive flavour – hints of caramel with overtones of toffee will not do – and a rare colour, amber set alight. Maple flavour is, well, maple flavour, uniquely different from any other."[36] Agriculture Canada has developed a "flavour wheel" that details 91 unique flavours that can be present in maple syrup. These flavours are divided into 13 families: vanilla, empyreumatic (burnt), milky, fruity, floral, spicy, foreign deterioration or environment, maple, confectionery, and plants forest-humus-cereals, herbaceous or ligneous.[56] These flavours are evaluated using a procedure similar to wine tasting.[57]
Maple syrup and its various artificial imitations are widely used as toppings for pancakes, waffles, and French toast in North America. They can also be used to flavour a variety of foods, including fritters, ice cream, hot cereal, and fresh fruit. It is also used as sweetener for granola, applesauce, baked beans, candied sweet potatoes, winter squash, cakes, pies, breads, tea, coffee, and hot toddies. Maple syrup can also be used as a replacement for honey in wine (mead).[58]
In the United States, "maple syrup" must be made almost entirely from maple sap, although small amounts of substances such as salt may be added.[59] "Maple-flavoured" syrups include maple syrup but may contain additional ingredients.[60] "Pancake syrup", "waffle syrup", "table syrup", and similarly named syrups are substitutes which are less expensive than maple syrup. In these syrups, the primary ingredient is most often high fructose corn syrup flavoured with sotolon; they have no genuine maple content, and are usually thickened far beyond the viscosity of maple syrup.[61] The fenugreek seed, a spice with high amounts of sotolon, can be prepared to have a maple-like flavour, and is used to make a very strong commercial flavouring that is similar to maple syrup, but much less expensive; one such syrup, Mapleine, was popular during the Great Depression.[62][63].
American labelling laws prohibit imitation syrups from having "maple" in their names.[64] In Canada, syrup must have a density of 66° on the Brix scale to be marketed as maple syrup.[26] Québécois sometimes refer to imitation maple syrup as sirop de poteau ("pole syrup"), a joke referring to the syrup as having been made by tapping telephone poles.[65]
Imitation syrups are generally cheaper than maple syrup, but tend to taste artificial. A 2009 Cook's Illustrated comparison between top-selling maple and imitation syrups consistently rated the real maple brands (Maple Grove Farms, Highland Sugarworks, Camp Maple, Spring Tree, and Maple Gold) above the imitation brands tested (Eggo, Aunt Jemima, Mrs. Butterworth's, Log Cabin, and Hungry Jack).[66]
Maple syrup and maple sugar were used during the American Civil War and by abolitionists in the years prior to the war because most cane sugar and molasses were produced by Southern slaves.[67][68] Because of food rationing during the Second World War, people in the northeastern United States were encouraged to stretch their sugar rations by sweetening foods with maple syrup and maple sugar,[12] and recipe books were printed to help housewives employ this alternative source.[69]
Maple products are considered emblematic of Canada, in particular Quebec, and are frequently sold in tourist shops and airports as souvenirs from Canada. The sugar maple's leaf has come to symbolize Canada, and is depicted on the country's flag.[70] Several US states, including New York and Vermont, have the sugar maple as their state tree.[71] A scene of sap collection is depicted on the Vermont state quarter, issued in 2001.