Maple trees are tapped by drilling holes into their trunks and collecting the sap, which is processed by heating to evaporate much of the water, leaving the concentrated syrup.
According to Indigenous oral traditions, as well as archaeological evidence, maple tree sap was being processed into syrup long before Europeans arrived in the region.
At the beginning of the spring thaw, they made V-shaped incisions in tree trunks; they then inserted reeds or concave pieces of bark to run the sap into clay buckets or tightly woven birch-bark baskets.
The maple sap was concentrated first by leaving it exposed to the cold temperatures overnight and disposing of the layer of ice that formed on top.
Following that, the sap was transported by sled to large fires where it was boiled in clay pots to produce maple syrup.
Contrary to popular belief, syrup was not typically produced by dropping heated stones into wooden bowls, especially in northeast North America where Indigenous cultures had been using clay pots for thousands of years.
[22] In the early stages of European colonization in northeastern North America, local Indigenous peoples showed the arriving colonists how to tap the trunks of certain types of maples during the spring thaw to harvest the sap.
[23] André Thevet, the "Royal Cosmographer of France", wrote about Jacques Cartier drinking maple sap during his Canadian voyages.
[26] 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".
[27] 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.
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 down to achieve the desired concentration.
[19][29] Around the time of the American Civil War (1861–1865), 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.
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.
[19] Heating methods also diversified: modern producers use wood, oil, natural gas, propane, or steam to evaporate sap.
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.
[40] In addition to open pan evaporation methods, many large producers use the more fuel efficient reverse osmosis procedure to separate the water from the sap.
[41] Smaller producers can also use batchwise recirculating reverse osmosis, with the most energy-efficient operation taking the sugar concentration to 25% prior to boiling.
Tap seasons typically happen during late winter and spring and usually last for four to eight weeks, though the exact dates depend on the weather, location, and climate.
[64][70][71] In 2017, the QMSP mandated increased output of maple syrup production, attempting to establish Quebec's dominance in the world market.
The Canadian Food Inspection Agency (CFIA) announced in the Canada Gazette on 28 June 2014 that rules for the sale of maple syrup would be amended to include new descriptors, at the request of the IMSI.
[80] As of 31 December 2014, the CFIA[81] and as of 2 March 2015, the United States Department of Agriculture (USDA) Agricultural Marketing Service[82] issued revised standards intended to harmonize Canadian and United States regulations on the classification of maple syrup as follows: As long as maple syrup does not have an off-flavour, is of a uniform colour, and is free from turbidity and sediment, it can be labelled as one of the A grades.
[87] With the new grading system, the classification of maple syrup depends ultimately on its internal transmittance at 560 nm wavelength through a 10 mm sample.
[78] Each maple syrup product must be verified clean if it follows a grade name or if it is exported out of the province in which it was originally manufactured.
It consists primarily of sucrose and water, with small amounts of the monosaccharides glucose and fructose from the inverted sugar created in the boiling process.
Maple syrup is generally low in overall micronutrient content, although manganese and riboflavin are at high levels along with moderate amounts of zinc and calcium (right table).
[96] Its brown colour – a significant factor in the appeal and quality grading of maple syrup – develops during thermal evaporation.
[103] One author 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.
[107][108][109] 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, fresh fruit, bacon, and sausages.
It is also used as sweetener for granola, applesauce, baked beans, candied sweet potatoes, winter squash, cakes, pies, breads, tea, coffee, and hot toddies.