Sap is made into maple syrup by boiling off the water, concentrating the sugar and minerals. During the process of evaporation, the heat causes chemical reactions in the concentrated sap, resulting in maple syrup with its characteristic flavor. The color and flavor of maple syrup are determined by the freshness of the sap and the speed of boiling. It takes about one cord of dry wood to make 20 gallons of maple syrup. It takes about 40 gallons of sap to make one gallon of syrup.
Maple syrup is governed by state law with respect to density, color and flavor.
During evaporation, minerals appear as a sediment known as sugar sand or niter, removed by filtering. The result is a crystal clear product. The hot syrup sterilizes the container and prevents the syrup from spoiling. Open containers should be kept refrigerated, and it's a good idea to keep all syrup cool. Maple syrup is graded by color, flavor and clarity.