Maple syrup mold may surprise you at the most inopportune of times - on your waffles or pancakes at breakfast. And once identified, what to do about it? For the sake of your health, is disposal of this delicious - and expensive - condiment necessary once the mold appears? The answer, in a word, is YES. Keep reading to learn about the unique evolutionary niche occupied by molds that live in maple syrup and why its presence is cause for concern.
Mold is one type of fungi. No one knows how many species of these fungi exist but estimates range from tens of thousands to perhaps three hundred thousand or more. Humans are mostly commonly exposed to molds from indoor air and food sources and exhibit a range of susceptibility to these fungi based on exposure concentration and whether the mold produces harmful mycotoxins.
Maple syrup mold
Molds that are found in maple syrup are special: they grow in extremely dry places. While most molds prefer to colonize moist, high-humidity areas, the xerophilic fungi found in syrup favor high-sugar (e.g., jam, dried fruit) or hyper-saline environments.  At first glance, maple syrup might not seem very "dry". Chemically, however, it certainly is. With the condiment's extremely high concentration of sugar, its water component is essentially unavailable to organisms - sugar absorbs much of the moisture that might otherwise be used by more common mold varieties. Thus, the xerophilic mold found in maple syrup is an interesting and unexpected example of evolution and niche competition in the 'wild.'
Mold on Maple Syrup
Where does it come from and is it harmful?
Molds infiltrate your home as hitchikers in the soil on your shoes and as rogue dust invisibly sneaking through open windows and doors. For example, one type of mold found in maple syrup, Wallemia sebi, has commonly been detected in agricultural- and house dust.
The research on xerophilic molds is evolving; however, some of these molds, including W. sebi, have been identified as potentially harmful when ingested. Because individual mold spores are not visible to the naked eye, physically removing large visible colonies is insufficient to ensure avoidance of a food-borne illness, and straining or re-heating moldy maple syrup does not guarantee adequate protection against harmful growths. Maple syrup with visible spore colonies should be disposed of; consistent refrigeration of maple syrup is the best way to prevent these unwelcome guests from ruining your breakfast.