As it grows, the sugar maple transforms starch into sugar. The sugar combines with water absorbed by the maple’s roots, slightly sweetening the maple water. In the spring, when temperatures begin to rise again, the water found in the trunk and roots expands, building up pressure inside the tree. The alternation of cold, sub-zero nights and days where the temperature rises above zero encourage the flow of maple water, which is then transported by tubes to the sugar shack. There, an evaporator turns the maple water into maple syrup. It requires an average of 40 litres of maple water to obtain one litre of syrup.