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. In cold climates, these trees store starch in their trunks and roots before winter; the starch is then converted to sugar that rises in the sap in late winter and early spring. 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. Most trees can produce 20 to 60 liters (5 to 15 US gallons) of sap per season