Off-Flavors Maple syrup is a natural product and thus varies in chemical composition. The biochemistry of the sap is the main factor influencing the color and flavor grade of the maple syrup produced. Sap not affected by microorganism activity will produce lighter grades of syrup with a subtle maple bouquet flavor. Sap affected by higher concentrations of microorganisms will produce darker grades of syrup.
Color changes occur early in the sap boiling process.
Rules and regulations for maple syrup grading are discussed elsewhere. The chemical development of maple flavors and off-flavors during the sap boiling process has not been clearly understood. Maple syrup flavor can be affected by many factors that occur before, during and after processing. Not all causes of off-flavors are traceable. Excess sodium in sap causes a salty flavor in syrup.