This Is How Long Maple Syrup Actually Lasts

Generally speaking, maple syrup keeps for months to years, but it varies a bit depending on how you store it. An unopened bottle of maple syrup can last an extremely long time. Some experts say an unopened, properly stored container lasts indefinitely, while others recommend a period more like three years. In any event, keep it in a cool, dark location, as heat or sunlight can impact quality. However, keeping maple syrup at room temperature isn't generally recommended.

Once you open maple syrup, things change a bit. When syrup is exposed to air, temperature fluctuations, and possibly moisture, its shelf life shortens. At that point the rules are more specific: Pure maple syrup should be stored in the refrigerator after opening. But if we're talking about pancake syrup versus maple syrup, then it's different since pancake syrup is more likely to contain preservatives. 

Refrigerated maple syrup typically keeps for six to 12 months while maintaining good flavor and texture. If you want to keep it even longer — especially if you don't use it often — freezing maple syrup is also a possibility. The high sugar content prevents it from freezing solid, and it can remain stable for years in the freezer. Make sure there's room in the container for the syrup to expand as it freezes, though. If you need to thaw it quickly, you can place the container in a bowl of warm water.

The good news is that since maple syrup is very high in sugar, it's unlikely to outright go bad (for example, with bacterial nasties growing in it). However, maple syrup can grow mold, especially if it's opened and stored at room temperature. If you notice a green or white film on top, or it portrays a slimy surface, those are clear warning signs. Other red flags include a sour or musty smell, noticeably off taste, or thick, grainy, or clumpy texture that wasn't there before. If you happen to buy maple syrup in a can, watch out for dented or otherwise damaged cans, as the seal may be broken, exposing the syrup to air and possible mold spores.

If you do see mold, some note you can salvage it. Maple syrup producers say to skim the mold off with a utensil and then re-sterilize the syrup by bringing it briefly to a light boil. Then you can store it cold again. That said, it may just be wiser to ditch the syrup and grab a new bottle or can, in the name of safety. Finally, when you want to pick the best maple syrup, remember it can feature different colors and varying levels of flavor intensity. Darker grades of syrup might retain their flavor for a fraction longer, but all the same rules more or less apply across all types of maple syrup.