Maple syrup is classified (graded) under guidelines set by the Canadian Food Inspection Agency. Typically, syrup harvested early in the season yields a lighter colour and more delicate flavour while syrup collected at the end of the season is darker with more robust flavour. All grades have the same sugar content (66-68% sugar).
Some consumers prefer the subtle flavour of light syrup while many others like the more robust flavour of dark syrup. The dark syrup typically produced at the end of the season is popular for cooking and baking as it is the heartiest grade with the heaviest maple flavour. It is not easily hidden by other ingredients and is a great sugar substitute in most recipes.