Maple syrup mold

I have some grade B maple syrup I got from a farmers market. I stupidly didn't realize it should be refrigerated after opening and it's been in my pantry for a month or so opened (I swear as a kid we never put our maple syrup in the fridge!!). This developed a thin mold skin on top. How safe is it to skim the mold off, strain it, boil it, put it into a glass jar in the fridge and continue to use? It's hard to get maple syrup where I am so really hoping I can salvage it!!



B N. August 14, 2016
Had the same problem this morning, however, the syrup had always been refrigerated. Planning to skim, boil and save.
LeBec F. January 4, 2014
curio, i have lived in new england all my adult life and most people have experienced that mold. UVM- follow them, per coookbookchick. Gosh, there are too many things one could worry about in this world and mold on a pure sugar item is not one of them, imo.
CurioCook January 4, 2014
Whoops - UVM not UVA!
CurioCook January 4, 2014
Thanks all -- my childhood syrup was most definitely real. We used to get a giant metal jug from the local maple syrup festival. I've gone the UVA route for now, but keeping an eye on it to see where it goes. Trena - this information is very helpful, and exactly what I'm worried about…. ergh. I tasted a little and it still tasted good and I haven't died… yet ;) I'll see where it goes from here…. Thanks!!
Trena H. January 4, 2014
The issue is that one doesn't know precisely the type of mold in the syrup. Here's a response from a mycologist at Cornell re: moldy syrup.

Wallemia is ONE of the molds that might be found floating in maple syrup. Other xerophiles might be found there as well.

Whether to throw out the syrup is a hard question to answer. How much mold is there? Does this fungus make toxins in that sugary environment? Are those toxins produced in enough quantity to hurt you? Isn’t it frustrating that I don’t know the answers? I generally tell people not to eat moldy food. At least with a solid food (like cheese?) you could theoretically cut around the mold and remove it (but cut deeply, because the mold extends further in than you might think!). In a liquid, any emitted toxins can diffuse right in, so removing the colony may not remove the toxins. I personally threw out my moldy syrup without further toxicological analysis… but not without some sadness.

Here's the link to the Cornell mycology blog
cookbookchick January 4, 2014
I would look on websites where maple syrup is sold for guidance. You might not have to toss it. Perhaps when you were a kid the maple syrup in the pantry was not real maple syrup?

Voted the Best Reply!

cookbookchick January 4, 2014
This, for example, is from the University of Vermont website: If, after extended storage, mold should form on the surface of the syrup, the original quality can be restored. Remove the mold, heat the syrup to boiling, skim the surface, sterilize the container, and refill it with the syrup.
cookbookchick January 4, 2014
Here's the whole storage description from UVM (though I must say I've never frozen mine - I keep it in the fridge): Storage Store maple syrup in your freezer to retain flavor and quality over an indefinite period of time. The syrup will not freeze solid and will require only about one hour at room temperature to bring it to pouring consistency. The amount required can be removed from the container, and the remainder may be returned to the freezer. If, after extended storage, mold should form on the surface of the syrup, the original quality can be restored. Remove the mold, heat the syrup to boiling, skim the surface, sterilize the container, and refill it with the syrup.
Mary A. September 18, 2019
Yes, but here's the thing. The information from University of Vermont is from experts on maple syrup. The information from Cornell is from mycologists, experts in mold. The experts in mold point out that we know know just which species of mold is growing in our syrup, and importantly, what toxins or enzymes it may be producing. Some of the toxins may be resistant to being broken down by heat. Some of the toxin or enzymes may have long range effects.. a liver cancer in people how have had hepatitis is mentioned as possible. While most molds may be perfectly benign, we don't know that for sure. So, who do you want to believe? We make those decisions individually. My decision is that I'll trust the mycologists about molds. Then maple sugar scholars need to catch up. When the maple sugar scientists can present long term studies about what exactly is in the moldy syrup, and what it's long term effects on living mammals are.. then I'll believe them about the safety of consuming moldy maple syrup.
LeBec F. September 18, 2019
mary, i'm still on the 'remove it and use it' bus, but i want to send you my admiration and appreciation for taking the time to educate us in such a thorough fashion. teacher? lawyer? it's in your blood! thx again,
Trena H. January 4, 2014
CurioCook - Toss it! This happened to me once and ever since I've stored my maple syrup in the fridge. Sorry :(
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