How To Tell Your Maple Syrup Has Spoiled
This is a public service announcement for pancake lovers: Before you use it, check to make sure your maple syrup is not spoiled. It is one of those pantry items that seems like it should last forever, but actually has a shelf life.
If stored properly, it is rare for maple syrup to go bad (via Does It Go Bad). It can be stored at room temperature as long as it is unopened. Once opened, maple syrup should be moved to the fridge for up to a year. In fact, the low temperature of the fridge combined with the high sugar content of syrup allows the product to last. *Moves syrup right now from the cabinet*
Although maple syrup spoiling is not common, there is a chance for mold. Keep in mind that we are talking about pure maple syrup, not pancake syrups like Log Cabin. According to the Kitchn, those syrups are made of maple flavoring and corn syrup, which create an entirely different shelf life.
What to do if maple syrup is moldy
Moldy maple syrup does not necessarily mean you have to discard it. Ben's Maple Syrup explains that it is safe and simple to remove the mold if done properly. Scoop the mold off of the top of the product and throw it away. Then, boil the maple syrup to make it safe for eating, and pour it into a new container. Voila — safe and delicious maple syrup.
Of course, if you are unsure of the mold and fear the syrup is not safe for consumption, simply toss it, although mold that grows in the syrup is non-toxic. In the scenario that the item smells sour or "funny," completely toss it. You do not want to take any chances. The best way to store maple syrup is to keep it in the freezer, as it will not freeze through.
An important factor to mention is the crystals that normally form on the bottom of the bottle. According to Does It Go Bad, this is neither harmful nor a sign of decay. Now, go eat those pancakes you have been craving!