How maple syrup is made

It takes 20 to 50 buckets of maple sap to boil down to a single bucket of syrup.

stations: 7
things upstream: 1
raw source: 1
step from the ground: 1

The short version

In late winter, maple trees are tapped and the sap, only a few percent sugar, runs through tubing to a sugar shack. Evaporator pans boil 20 to 50 volumes of sap down to one of syrup, ending a few degrees above the boiling point of water. The syrup is filtered and packed hot.

Drill the tap holes

In late winter, starch stored in the trunk turns to sugar and rises with the sap. Workers drill into trunks and set spouts. A tree is usually tapped beginning at 30 to 40 years of age, with one to three taps depending on trunk size.

Goes in
Maple sap
Pipe the sap downhill

Plastic tubing runs the sap from tree to tree and on to a central tank, often helped by vacuum pumps. An average tree gives 35 to 50 litres over a whole season.
Preheat the sap

The sap is warmed with hot vapor from the evaporator, which saves fuel. Sap at this stage is only two to five percent sugar.
Boil it down

In a shallow evaporator pan, between 20 and 50 volumes of sap are boiled to get one volume of syrup. Sweeter sap needs less. Sap at 1.5% sugar takes 57 units to make 1, and sap at 3.5% takes 25.
Draw off at the right density

The syrup maker watches the boiling point. Syrup is done at about 4.1 °C above the boiling point of water, or 66 on the Brix scale. Boiled too long, it crystallizes. Under-boiled syrup is watery and spoils quickly.

66 Brix
Filter out sugar sand

Hot syrup passes through a filter press that catches sugar sand, tiny crystals of sugar and calcium malate, which would cloud the syrup.
Grade and pack hot

Syrup is graded by color and taste and packed into containers at about 82 °C or hotter. The sealed containers are tipped over so the hot syrup sterilizes the cap.

End of the lineMaple syrup

Worth repeating

Quebec alone makes 72% of the world's maple syrup.
In Canada, maple syrup must be at least 66 percent sugar and made only from maple sap.
Maples can keep being tapped until they are over 100 years old.