Does Maple Syrup Expire?
Does Maple Syrup Expire?
Maple syrup lasts a long time — but it doesn’t last forever. Like most real foods, pure maple syrup can spoil under the wrong conditions.
The good news: if you store it properly, maple syrup can stay good for years.
This guide explains how long maple syrup lasts, what causes spoilage, how to store it correctly, and how to tell if a bottle has gone bad.
Short Answer: Yes, but it takes a while
Unopened, pure maple syrup does not really “expire” in the way fresh food does. Because it’s high in sugar and low in water activity, it resists bacterial growth. That’s why properly sealed maple syrup can remain shelf-stable for years.
Once opened, maple syrup should be refrigerated to prevent mold growth. If left at room temperature after opening, it can spoil.
If you want to understand what qualifies as “real” syrup in the first place, start here: Michigan Maple Syrup.
How long does maple syrup last?
Unopened: Properly sealed pure maple syrup can last several years when stored in a cool, dark place.
Opened: Once opened, maple syrup should be refrigerated and is best used within 6–12 months for optimal flavor and quality.
Commercial bottling and proper sealing dramatically extend shelf life, but refrigeration after opening is non-negotiable.
Why maple syrup can spoil
Maple syrup spoils primarily because of mold, not bacteria. Mold can grow on the surface if syrup is diluted by condensation or left unrefrigerated after opening.
This doesn’t mean the syrup is “toxic,” but it does mean quality and safety are compromised if mold growth is ignored.
Is moldy maple syrup dangerous?
Surface mold on maple syrup is common and usually white or gray. Traditionally, mold can be removed by skimming and re-boiling the syrup — but most producers recommend discarding contaminated syrup at home to avoid risk.
Bottom line: If you see mold and don’t know how the syrup was handled, it’s safest to toss it.
Does maple syrup go bad faster in plastic or glass?
Maple syrup lasts longest in glass containers, which don’t absorb odors or allow oxygen transfer. Plastic containers are convenient but may slightly shorten shelf life once opened.
Regardless of container, refrigeration after opening matters more than packaging type.
Does grade affect shelf life?
No. Maple syrup grade affects flavor, not shelf life. Light and dark syrups store the same way.
If you want to understand the differences between grades and how they’re used, read: Maple Syrup Grades Explained.
Does maple syrup ever ferment?
If syrup is diluted or improperly stored, fermentation can occur. Signs include off smells, bubbling, or a sour taste.
Fermented syrup should not be consumed.
Best way to store maple syrup
- Store unopened syrup in a cool, dark place.
- Refrigerate immediately after opening.
- Keep containers tightly sealed to prevent contamination.
Treat maple syrup like the real food it is — not a shelf-stable artificial syrup.
Does this apply to imitation syrup?
No. Imitation syrups made from corn syrup and preservatives behave very differently and are often shelf-stable after opening.
That difference is one of the reasons people choose pure maple syrup instead.
If you want to understand why purity and handling matter, read: Why Our Maple Syrup.
Shop maple syrup
Browse our current syrup here: Shop Maple Syrup.
See everything we make: Shop All Products.
Buying for someone else? Let them choose: Bonz Beach Farms Gift Card.