In the U.S. syrup grading system, grade B maple syrup is a dark syrup that is primarily used for baking and cooking. It has a strong flavor with a slight caramel taste.
Grade B maple syrup is darker and thicker than grade A syrup. Grade A syrup is the type of syrup typically used for eating, such as on waffles or pancakes. Grade A syrup has three sub-grades based on syrup color, including light amber, medium amber and dark amber. Grade B syrup is darker and richer because it comes from sap collected later in the season. Sap collected in the beginning of the season has a lower concentration of sugar and thus produces paler syrup with a lighter flavor (grade A). As the season goes on, the sugar concentration increases, creating a more flavorful syrup (grade B).
Canada, the producer of more than 80 percent of the world’s maple syrup, has its own syrup grading system. The Canadian system has four letter grades, with grade B being "medium." Vermont, credited with producing 5 percent of the world's maple syrup, also has its own classification system with slightly stricter standards.