Maple sap on average is about two percent sugar, but the sweetness can vary dramatically from one tree to another. Soon after it is gathered, the sap is heated to concentrate it into syrup or sugar. It takes about 40 gallons of sap to make 1 gallon of syrup. Sap becomes syrup when it is 66 to 67 percent sugar. A less concentrated product can sour. With additional heating, a gallon of maple syrup makes about 8 pounds of maple sugar.
