The Only Way to Store Maple Syrup, According to an Expert

While Costco’s Kirkland Pure Maple Syrup is a popular buy—it only costs about $15 for 1 liter, depending on the season—storing the product properly is important. After all, those large-size goods are an investment and you don’t want them to go to waste. While some have straightforward directions, others have been found at the center of social media debates such as how to store ketchup and whether butter actually requires refrigeration. 

It’s important to double-check the label, especially on condiments where storage best practices might not always be common knowledge. Unfortunately, more than a few shoppers have had to learn this lesson the hard way when it comes to maple syrup. For years, Costco members have been sharing their experiences on Reddit after noticing mold in their pantry-stored maple syrup. The label indicates that refrigeration is required after opening but many say they have completely overlooked the note. 

While Costco members have been vocal about their Kirkland maple syrup mishaps, it’s not limited to one brand. In fact, mold can grow in any container of pure maple syrup, particularly if it’s not stored correctly. This not only risks wasting a hefty investment but also ruining your stack of good old-fashioned pancakes.

To find out the safest way to store pure maple syrup, we reached out to Mark Isselhardt, a maple specialist at the University of Vermont Extension’s Proctor Maple Research Center.

The Best Way To Store Pure Maple Syrup

Unlike pancake syrup, also known as imitation maple syrup, pure maple syrup doesn’t have any preservatives. This, in addition to its water content, makes it prone to spoilage when not stored correctly. According to Isselhardt, the best place to store maple syrup after opening it is in the refrigerator, where it can last for about a year. Refrigerated maple syrup will remain pourable but it may develop some harmless sugar crystals over time. 

If you regularly purchase bulk-size pure maple syrup jugs for your family but don’t go through them quickly, it may be a good idea to opt for smaller bottles that better fit your habits. If the bulk prices are too good to pass up, don’t worry. Isselhardt suggests an alternative you may have not considered: freezing your syrup. 

“One option that can save money and keep syrup as fresh as possible is to freeze the syrup,” he explains. “To do this, purchase a gallon of syrup and store most of that volume in clean, glass canning jars in the freezer. Syrup is only about 33 percent water so it won’t freeze and break the glass. The remaining syrup can be left in the refrigerator and refilled as needed.”

Freezing your maple syrup will allow you to avoid the risk of spoilage and continue to get the most out of your investment.

How To Tell If Your Maple Syrup Has Spoiled

If you’re questioning the quality of a bottle of maple syrup in your cabinet right now, there are a couple of ways to quickly tell if yours has gone bad. 

“Visible clusters of mold floating on the surface of the syrup is one indication that the product is spoiled,” Isselhardt says. ”Sometimes there is no visible mold on the surface but there is floating material suspended in the syrup. If consumers see something off when pouring out some syrup, they might consider transferring it to a large clear bowl or container.” 

If you do notice mold in your syrup, you should not attempt to remove it or boil the syrup to make it edible. This was a popular subject across many Reddit threads but our expert explains that while this was once a common practice, it is no longer advised. “The byproducts of mold growth may be infused in the syrup and these newly formed compounds are not always susceptible to syrup boiling temperatures,” Isselhardt notes.

In other words, there may still be traces of mold in your syrup even after boiling, so it’s best to toss it and start fresh. 

In addition to visible signs of spoilage, you can also tell if your maple syrup has gone bad by tasting it. Maple syrup that lacks its distinct flavor, tastes chocolatey like a Tootsie roll, or is sour indicates there is an issue with the batch. 

So, if you’ve been storing your real maple syrup in the cabinet, it’s a good idea to pour some out and make sure it’s still good. And from now on, be sure to pop the bottle into the refrigerator so the next time you whip up a batch of maple fudge or pure maple candy, you can rest assured knowing that your syrup is fresh and free of mold.