Can you use maple syrup that has mold?

Quick Answer

It is generally not recommended to use maple syrup that has visible mold growth. Mold can produce toxins that pose health risks. Small amounts of mold growth may be harder to see, so it is best to discard maple syrup if you see any mold, fuzz, orspots that could be mold.

What is Maple Syrup?

Maple syrup is a sweet, thick syrup made by boiling down the sap from maple trees. It takes about 40 gallons of maple sap to make 1 gallon of syrup. Pure maple syrup contains just one ingredient – maple sap. It has a rich maple flavor and is used as a topping for foods like pancakes and waffles.

How is Maple Syrup Made?

Making maple syrup involves gathering and boiling down the sap from maple trees. Here is the basic process:

  • Tap maple trees by drilling holes and inserting a spout called a spile. This allows the sap to drip out into a container.
  • Collect the sap and transport it to an evaporator.
  • Boil the sap down to syrup. It takes heat and time to remove excess water, increasing the sugar concentration.
  • Filter the syrup to remove impurities.
  • Grade, bottle, and store the finished maple syrup.

Maple Syrup Nutrition

Maple syrup contains:

  • Calories: 60 calories per tablespoon
  • Carbs: 17 grams per tablespoon
  • Sugar: 13 grams per tablespoon
  • Small amounts of minerals like calcium, potassium, and manganese
  • Antioxidants including phenols and flavonoids

Can Maple Syrup Get Moldy?

Yes, maple syrup can get moldy. Maple syrup’s thickness and sugar content make it unlikely to grow mold. However, mold can grow if the syrup is contaminated or stored improperly.

Causes of Moldy Maple Syrup

Maple syrup can grow mold due to:

  • Contamination – Bits of mold, yeast, or bacteria get into the syrup during production, bottling, or storage.
  • Oxygen exposure – Headspace or cracks in the container allow oxygen to reach the syrup. Mold needs oxygen to grow.
  • Humidity – Storage in humid environments makes it easier for mold to grow.
  • Warm temperatures – Warm spots in storage areas promote faster mold growth.

Identifying Mold in Maple Syrup

Look for the following signs of mold growth in maple syrup:

  • Spots – Look for small spots or dense areas that look different than the surrounding syrup.
  • Fuzzy growth – Mold has a characteristic fuzzy, cotton-like appearance.
  • Webbing – Some types of mold produce thin, spiderweb-like strands.
  • Color changes – Patches may appear lighter, darker, or greenish compared to the amber syrup.
  • Texture changes – Areas with mold may be thicker or take on a gelatinous texture.

Is Maple Syrup with Mold Safe to Eat?

No, it is generally unsafe to eat maple syrup once it has mold. Even a small amount of mold can contaminate the entire container. All mold should be considered potentially dangerous.

Health Risks of Eating Moldy Maple Syrup

Eating maple syrup contaminated with mold can lead to:

  • Allergic reactions – Mold allergies can cause hives, asthma attacks, and other problems.
  • Respiratory problems – Inhaling mold particles can irritate lungs and worsen conditions like asthma.
  • Gastrointestinal issues – Mold ingestion can lead to nausea, vomiting, diarrhea, and belly pain.
  • Mycotoxin poisoning – Dangerous substances produced by mold that cause illness.
  • Severe infections (rare) – In very rare cases, dangerous molds like Aspergillus can cause serious lung infections.

At risk groups including infants, young children, elderly, pregnant women, and those with weakened immune systems are especially vulnerable to mold toxins. Healthy adults may get sick from eating moldy syrup too.

No Level of Mold Exposure is Safe

Even small or unnoticeable amounts of mold in syrup can produce mycotoxins that lead to health issues. Mold can have roots that extend invisible into syrup, well beyond visible mold spots. These roots can release toxins that contaminate areas that look normal.

Toxicity Depends on the Mold Type

Some types of mold produce more dangerous toxins. But it is impossible to identify mold types and toxin levels by sight alone. Never assume a mold is safe based on its appearance.

Toxicity Increases Over Time

The longer mold grows, the more toxins it produces. Letting moldy syrup sit gives the mold time to generate more toxic substances.

What to Do With Maple Syrup with Mold

If you discover mold growth in your maple syrup, you should:

  1. Discard the maple syrup – Do not eat any syrup containing mold.
  2. Clean the container thoroughly – Use hot, soapy water then rinse.
  3. Replace plastic lids – Mold can penetrate porous plastic meaning the lid should be tossed too.
  4. Watch for illness – Monitor your health for any signs of illness over the next few days and weeks in case you ingested mold.
  5. Check your pantry – Inspect all food items for possible contamination sources.
  6. Adjust storage conditions – Take steps to lower humidity levels and avoid temperature fluctuations.

How to Prevent Mold Growth in Maple Syrup

You can discourage maple syrup mold growth by:

  • Buying small bottles – Small containers are used up quicker before mold can grow.
  • Storing in refrigeration – The cold environment slows mold growth.
  • Keeping lids tight – Prevent oxygen from reaching the syrup.
  • Checking regularly – Look for signs of mold when getting out syrup.
  • Wiping rims – Clean drips to avoid sticking spores and promote full lid sealing.
  • Using clean utensils – Don’t introduce contamination through dirty spoons, etc.
  • Avoiding temperature fluctuations – Keep storage spots consistently cool.

Maple Syrup Storage Tips

Proper maple syrup storage helps prevent mold growth. Recommendations include:

  • Refrigerate after opening – Keep unused syrup chilled in the fridge.
  • Store in smaller bottles – Transfer syrup to smaller containers with less airspace.
  • Check seals periodically – Ensure lids are tight and fully preventing air exchange.
  • Keep dry – Avoid overly humid pantries which encourage mold growth.
  • Watch for signs – Discard immediately at the first sign of mold.
  • Don’t double dip – Use a clean spoon each time to prevent contamination.

Can You Remove Mold from Maple Syrup?

It is not recommended trying to remove mold from maple syrup. Mold contamination makes the entire batch unsafe for consumption. Attempting to scoop out visible mold does not remove unseen contamination.

Heating or boiling maple syrup will kill mold spores. However, it does not neutralize harmful mycotoxins. While boiling may make the syrup look normal, toxins can still be present and make you sick.

Likewise, do not attempt to mix out mold spots by stirring contaminated syrup. This spreads mold throughout the entire container.

There is no reliable way to rescue a batch of maple syrup once mold has started growing. Your safest option is to discard the syrup to prevent health risks.

Can You Make Maple Syrup from Sap with Mold?

No, maple sap containing visible signs of mold growth should not be used to produce syrup. Mold in the sap can survive the boiling process and end up contaminating the finished syrup. Even a small amount of mold can release toxins. For food safety, start the syrup making process with clean sap only.

Checking Sap for Mold

Examine maple sap closely for mold contamination before boiling including:

  • Look at tubing, containers, lids, etc for visible mold.
  • Watch for web-like mold strands floating in the sap.
  • Feel for gritty particles that could be mold spores.
  • Smell for musty or rotten odors indicative of mold.
  • Taste a small sip of raw sap to check for unusual flavors.

Discard any sap that shows possible signs of mold growth. Protect your syrup quality by starting with fresh, mold-free sap.

Can Maple Syrup be Contaminated Without Visible Mold?

Yes, maple syrup can contain mold contamination even if no mold is visually apparent. Small amounts of mold growth or spores in the syrup may not be readily visible. But it can still release toxins that make the syrup unsafe to eat.

Hidden Signs of Contamination

Maple syrup may still be contaminated even without obvious mold if:

  • The syrup tastes off or fermented.
  • You detect a musty or sour maple syrup smell.
  • You see tiny bubbles indicating fermentation.
  • The syrup was exposed to mold but looks normal.
  • Any container leaks or damage occurred that could introduce mold.

When in doubt, play it safe and discard maple syrup with any hint of mold concern. The health risks are not worth taking a chance.

How Long Does Maple Syrup Last Before Molding?

Unopened maple syrup can last 12 months or longer before mold development if properly stored. Once opened, maple syrup mold can grow after 1-3 months without refrigeration. The shelf life shortens as more air reaches the syrup.

Unopened Maple Syrup Shelf Life

Sealed bottles of pure maple syrup can last:

  • 1 year at room temperature.
  • 2 years if refrigerated.
  • Up to 3 years frozen.

Improperly sealed containers may allow oxygen exposure and humidity leading to earlier mold growth.

Opened Maple Syrup Shelf Life

Once opened, maple syrup should be used quicker to avoid mold development:

  • 1-3 months in the pantry
  • 6-12 months refrigerated
  • 1-2 years in freezer

Transfer syrup to smaller containers and ensure tight seals to maximize leftover shelf life.


Maple syrup can grow mold if exposed to contamination or improper storage conditions. Visible mold as well as hidden mold growth makes maple syrup unsafe for eating due to health risks. There is no reliable way to remove mold from maple syrup once it develops. Discard all maple syrup immediately at the first signs of mold. Follow proper storage methods like refrigeration and small containers to extend maple syrup’s shelf life and prevent mold growth for as long as possible.

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