How to store maple syrup

In this brief guide, we will answer the question “how to store maple syrup?” with an in-depth analysis of the proper storage of maple syrup. Moreover, we will also discuss the nutritional value of maple syrup.

How to store maple syrup?

You should store an unopened bottle of maple syrup keeping it in a dry, dark, and cool area, away from heat sources such as sunlight and stovetops. Although not mandatory, refrigerating unopened syrup is recommended to ensure better preservation.

After Opening, seal tightly and refrigerate at all times. Unlike some commercial syrups, natural maple syrup does not contain added preservatives, making refrigeration necessary to maintain its freshness.

Freezing maple syrup can help you preserve it for a longer time.  (1)

How is maple syrup prepared for storage?

Traditionally, maple syrup is packaged at the “draw off” temperature, which ranges from 99°C to 103°C. This temperature is achieved either directly from the evaporator or the finishing pan. 

Alternatively, after storage, the syrup is reheated to a minimum temperature of 82°C before immediate packaging.

Once filled, the containers of maple syrup naturally cool down. To ensure sterilization of the headspace and closure, the container is inverted or laid on its side. 

This step helps prevent bacterial or fungal contamination. Failure to sterilize the container may result in changes to the syrup’s chemistry, including alterations in color and flavor. 

Additionally, there is a risk of potential toxicity due to the presence of mycotoxins. It is therefore important to ensure proper sterilization of containers to maintain the quality and integrity of the maple syrup. (1)

What are the signs of spoiled maple syrup?

The main signs of maple spoilage are mold growth, off odor and off taste.

Mold growth on the surface of maple syrup is an obvious indicator of product defect. While mold spores are resistant to heat, the extensive evaporation process during syrup production is generally effective in eliminating fungal contaminants. 

Thus, the presence of any mold in maple syrup is likely due to improper sanitation, low bottle filling temperature, or inadequate adherence to good manufacturing practices.

One way to assess the freshness of maple syrup is by giving it a sniff. If you detect an off-putting aroma, such as a sour or yeasty smell, it is best to discard the syrup to maintain quality.

If the maple syrup does not taste as it should, it is advisable to discard it for quality reasons. Unpleasant or off flavors may indicate spoilage or degradation of the syrup.

By being vigilant about mold growth, paying attention to odor, and evaluating the taste, you can ensure the maple syrup you consume is of high quality and enjoyable. (2)

Is it safe to consume expired maple syrup?

No, consuming expired maple syrup can lead to food poisoning and pose various health risks. Symptoms of food poisoning may include headaches, vomiting, stomachaches, and diarrhea, along with 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 essential to seek medical attention.

To avoid health issues, it is crucial to be aware of any signs of spoilage, such as an unusual smell or discoloration, as they indicate that the syrup has deteriorated and should not be consumed. 

If you notice mold growth in the maple syrup, it is best to dispose of it promptly to prevent potential health hazards. Your well-being is of utmost importance, so exercising caution when dealing with spoiled food is crucial for maintaining good health. (3, 4)

How long does maple syrup remain good once opened?

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. 

Maple syrup, prior to opening, can be stored in the pantry for approximately one year. (5)

Can maple syrup go moldy?

Yes, molds can be formed on the surface of maple syrup.Aside 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. 

While mold spores have high thermal tolerance, it is generally believed that the extensive evaporation process involved in producing finished syrup effectively eliminates fungal contaminants. 

Therefore, the occurrence of mold in maple syrup is likely attributed to inadequate sanitation, low bottle filling temperature, or a lack of adherence to proper manufacturing practices. (2)

What are the causes of maple syrup spoilage?

Spoilage can be caused by physical contaminants such as minerals, wood chips, dust, or ash, as well as microbial factors like yeast and fungi. It’s important to note that maple syrup doesn’t have an expiration date. 

Maple syrup is derived from concentrating the xylem sap of the sugar maple tree (Acer saccharum). While the sap remains sterile when inside the tree’s xylem, it becomes highly susceptible to microbial growth when exposed to the environment. 

Factors such as changes in environmental conditions (as sap flow is weather-dependent), improper sap storage, or unsanitary processing practices can contribute to contamination.

Contamination can result in various forms of defective sap, leading to a lower quality syrup. Fungi have the potential to contaminate syrup regardless of the sugar content. 

Failure to properly sterilize containers can lead to bacterial or fungal contamination, which can affect the syrup’s chemistry, resulting in changes to its color and/or flavor. 

In some cases, mycotoxins may be present, potentially causing toxicity. It is therefore important to prioritize container sterilization and adhere to good manufacturing practices to minimize the risk of contamination and maintain the quality and safety of maple syrup. (1, 2)

What other changes can occur during storage?

Syrup can undergo several changes during storage. If maple syrup is stored in plastic containers, it is susceptible to darkening over time. This darkening occurs because oxygen can permeate through the plastic, leading to oxidation of the syrup.

Furthermore, if the container is not properly sterilized, bacterial or fungal contamination can occur. This contamination can impact the chemical composition of the syrup, resulting in changes to its color and/or flavor before it reaches the point of spoilage.(1, 2)

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 answered the question “how to store maple syrup?” with an in-depth analysis of the proper storage of maple syrup. Moreover, we discussed the nutritional value of maple syrup.


  1. 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.
  2. Perry Jennifer J. A Comprehensive Review of Maple Sap Microbiota and Its Effect on Maple Syrup Quality. Food Reviews International 38, 2022.
  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?.