The sap run
Sugar maple and red maple convert the starch stored during the growing season into sugar. This sugar combines with the water absorbed by the tree’s roots. In the spring, when temperatures rise, the sweet sap in the trunk and roots expands, creating pressure inside the tree. The cycle of freezing at night and thawing in the day causes the sap to flow, at which point it is harvested.
The evolution of harvesting and production technology
Prior to 1850: Tapping is done with an axe, and sap is collected in birch bark containers or wooden pails.
Around 1850: Wood spouts are introduced.
Around 1870: Steel spouts and pails are introduced.
1872: The first evaporator.
Around 1925: Effective methods are preserving syrup are introduced. The 5 and 10 pound sugar loaves previously used to preserve maple sugar gradually disappear.
Around 1950: The classic 26 oz. (540 ml) can we still have today appears on store shelves.
Late 70s: Two major, back-to-back innovations revolutionize maple sugar production: tubing and reverse osmosis.
The night time freeze/daytime thaw cycle causes sap to flow.
Maple sap is collected using tubes attached to spouts tapped into the trees. These tubes are connected to collector pipes that carry the maple sap, by gravity or pumping, to the sugar shack.
At the sugar shack, the maple sap is collected in huge stainless steel tubs and sent to the osmosis unit before it is boiled and turned into maple syrup.
The osmosis unit is used to concentrate the sugar content of the maple sap (e.g., bring the concentration level from 3% to 20%).
This step lowers heating costs as well as the environmental impact of boiling.
The filtrate from the osmosis process is almost sterile water, which is used to clean the equipment and the shack.
The concentrated sap is then boiled with care according to a very precise process. It becomes maple syrup when it reaches 66°Brix degrees, or 66% sugar.
The maple syrup is then transferred to sterilized barrels for delivery to PPAQ authorized buyers.
Today, 98.5% of maple sap is collected with tubes, and 90% of that sap goes through the osmosis unit before being boiled into maple syrup.