Anyone who has bought a bottle of maple syrup has undoubtedly asked themselves the question: "does maple syrup go bad?" Nobody wants their expensive and beloved maple syrup to potentially spoil. But the question still remains, does maple syrup go bad, and if it does, how can you tell that it has expired?
The short answer is yes; maple syrup can go bad when stored under improper conditions. Maple syrup has a shelf life of over a year if unopened and can last for about a year if refrigerated (1). Bottles should always be placed in a cool, dark environment like a pantry, cupboard, or cabinet. Once opened, maple syrup should be placed in the refrigerator. By using these methods, maple syrup can last up to a year or even longer, but it is best practice to use all maple syrup within a year of opening just to be safe.
How does maple syrup go bad?
Maple syrup is a naturally made product that, like almost all other produce (with the notable exception of honey), will eventually go bad. But why does this happen? Maple syrup is the boiled down and refined tree sap of a maple tree. The boiling process evaporates most of the water in the tree sap, resulting in concentrated sugary syrup. This sugary syrup turns out to be the culprit when it comes to spoilage.
Oxidation of the sugars in maple syrup allows for mold to eventually grow on the surface of an opened bottle. Think of the process like the oxidation and gradual browning of a split apple or banana peel. Oxidation paired with warm temperatures creates the perfect conditions required for maple syrup to go bad.
How can I tell if my maple syrup has gone bad?
Usually, you will be able to tell if your maple syrup has spoiled. Typically an opened bottle placed in a warm and bright environment will be the first to turn bad. A foul smell paired with an off-taste is a telltale sign of spoilage. Syrup that has gone bad will taste chocolatey and bitter; some have described it as the taste of cardboard. Sometimes mold or discoloration will also be visible throughout or on the surface of an opened bottle of maple syrup.
Unopened maple syrup storage
When considering how maple syrup goes bad, a few preservation tips come to mind. Knowing that maple syrup can spoil only if it is open or improperly stored, it is important to prioritize good storage habits. To maximize shelf an unopened bottles shelf life, buyers can:
- Store maple syrup unopened in a cool and dark place for about a year or more.
- Purchase maple syrup in glass bottles that limit the possibility of oxidation.
Opened maple syrup storage
Storing an open bottle of syrup is a different story. Opened maple syrup, once exposed to oxygen, has a greater potential for oxidation and mold contamination. It is for this very reason that farmers bottle maple syrup at high temperatures where they eliminate any potential for mold growth (2). Maple syrup bottles that are open should be stored in the refrigerator, where they will stay good for a year. Refrigeration, as with all other foods, will slow down the bacterial activity of any possible contaminants.
Conveniently, freezing an opened jar of maple syrup will allow for an indefinite storage time. Freezing a bottle does not change its flavor and is a great way to prevent spoilage.
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Vermont Maple Syrup makes the best organic Vermont maple syrup, maple sugar, and maple candy you will taste. In classy, nostalgic packaging that puts Vermont first. Organic, pure small-batch maple syrup and maple sugar — tapped, collected, and made available from our 1,200-acre farm in the small town of Guilford, Vermont, USA.
