Can maple syrup mold?

In this brief guide, we will address the query, “can maple syrup mold?” We will also discuss what is the shelf life of maple syrup and how you can tell when it has gone bad.

Can maple syrup mold?

Yes, maple syrup can mold. Apart from variations in syrup grade caused by microbial sap spoilage, the presence of a visible fungal mat on the syrup’s surface is a clear indication of product defect. 

Despite mold spores’ considerable heat resistance, the extensive evaporation process employed in producing finished syrup is believed to be effective in eliminating fungal contaminants. 

Consequently, the occurrence of any mold in maple syrup is most likely attributed to inadequate sanitation practices, low bottle filling temperatures, or the absence of proper manufacturing protocols. (1)

Fungal contamination can affect syrup regardless of its °Brix measurement, which represents the dissolved solids in a liquid, often used to gauge the sugar content in an aqueous solution. 

Nonetheless, maple syrup producers generally believe that contamination is more likely to occur when packing syrup at a density below 66.0 °Brix. Lower °Brix levels provide more available water for microbial growth.

When containers are not properly sterilized, bacterial or fungal contamination can impact the chemistry of the syrup, leading to alterations in color and/or flavor. Additionally, there is a potential risk of mycotoxin-induced toxicity. (2)

Can you eat moldy maple syrup? 

No, the consumption of moldy maple syrup can lead to food poisoning and various health problems. Symptoms of food poisoning may manifest as headaches, vomiting, stomachaches, and/or diarrhea. 

Additionally, individuals may experience a loss of appetite and feelings of nausea. Generally, these symptoms should resolve within a day or two. However, if they persist beyond this timeframe, it is recommended to seek medical attention.

It is important to note any indications of spoilage, such as an unusual smell or discoloration, as they suggest that the syrup has deteriorated and should not be consumed. 

If the maple syrup shows signs of mold growth, it should be promptly discarded to prevent any potential health risks. (3, 4)

Can the syrup change during storage and still be safe to consume?

Yes, syrup can undergo changes during storage and still remain safe for consumption. If stored in plastic containers, the syrup may gradually darken over time. This darkening occurs because oxygen can permeate through the plastic, causing oxidation.

However, it is important to note that bacterial or fungal contamination resulting from improper sterilization of the container can impact the chemical composition of the syrup. 

This can potentially cause changes in the syrup’s color and/or flavor before it reaches a spoiled state. 

Reheating the syrup to a temperature of 93°C (199°F) will help achieve the desired level of sterility, assuming that the syrup cools down during the process of dispensing it into containers.(1, 2)

How to store maple syrup?

Proper storage is key to enlarging the shelf life of your products. You must take into consideration several recommendations to preserve maple syrup for a longer period.

Make sure you keep in mind several recommendations, such as

  • Place your maple syrup in a space that is dry and cool. Keeping maple syrup away from humidity will prevent mold growth. Also, when exposed to high temperatures, spoilage can happen rapidly.
  • Store maple syrup inside the fridge once you have opened the bottle. Make sure you seal it tightly before doing so.
  • Freezing maple syrup can help you preserve it for a longer time. However, you need to follow several steps to do it properly (2)

What is the shelf life of maple syrup?

Maple syrup, prior to opening, can be stored in the pantry for approximately one year. However, once opened, authentic maple syrup should be stored in the refrigerator, where it will remain fresh for about a year. 

On the other hand, opened containers of imitation maple syrup can be stored in the pantry for approximately one year.(5)

Other FAQs about Maple Syrup that you may be interested in.

How to can maple syrup

Substituting maple syrup for honey

Can maple syrup go in the fridge?


In this brief guide, we have addressed the query, “can maple syrup mold?” We have also discussed other queries related to the subject at hand. 

Hope you found this blog useful. If you have any questions, please let us know.


  1. Perry Jennifer J. A Comprehensive Review of Maple Sap Microbiota and Its Effect on Maple Syrup Quality. Food Reviews International 38, 2022.
  2. Mary Lynn Whalen and Maria Franca Morselli. Fungi Associated with Pure Maple Syrup Packed at the Minimum Recommended Reheating Temperature. Journal of Food Protection,47, 688-689, 1984.
  3. BM Lund, SJ O’Brien, Public Health Measures: Food Safety in Hospitals and Other Healthcare Settings, Encyclopedia of Food Safety, Academic Press, 2014, 140-148.
  4. Food Safety
  5. U.S. Department of Agriculture. Website. Washington, DC. How long can you keep maple syrup?.

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