Can You Ferment Maple Syrup?

I think we can all agree that maple syrup is pretty similar to honey. One of the things I love about honey is that it can be fermented to make mead. So if honey can be fermented, can you ferment maple syrup?

The answer is yes. Maple syrup can be fermented to make traditional ales and a unique alcohol called acerglyn. In fact, maple syrup producers actually used to take the last saps of the season, which were darker and less appealing, and ferment them for enjoyment over the winter.

Fermenting maple syrup is a wonderful tradition, so let’s learn more about this unusual alcohol.

wooden spoon glass bottle of maple syrup

Can Real Maple Syrup Ferment?

Generally speaking, maple sap itself, while naturally high in sugar, isn’t sugary enough to ferment. Maple syrup, which has been cooked to elevate and concentrate the sugars, is not only suitable for fermenting but sometimes will ferment naturally by itself.

Fermenting maple syrup into alcohol is very similar to making mead, an alcohol made by fermenting honey. It requires basic home brewing equipment, which typically includes:

  • A primary fermenter
  • A carboy/secondary fermenter
  • Airlocks
  • A hydrometer
  • A thermometer
  • Brewer’s yeast (there are many different yeasts and activators available, and each will lend other properties to the final result)
  • Containers, siphons, bottles, etc.

What Can You Make by Fermenting Maple Syrup?

Fermenting maple syrup in different ways can create a wide range of other beverages. Brewed with honey – like mead – fermented maple syrup is called acerglyn. It can also be brewed into ale, where brewers can optionally add hops to enhance the flavor. Maple syrup can also be added when fermenting hard apple cider, adding unique sweetness and flavors perfect for fall.

Some wineries are also making incredibly popular maple wines, following the traditional winemaking and aging processes, but with maple syrup.

Some adventurous distilleries are also making hard liquor and spirits from maple syrup, but, again, they tend to be using it in smaller quantities as a flavoring agent instead of a primary sugar.

If you’re making maple syrup at home, following traditional homebrewing methods with maple syrup will naturally create alcohol. However, most brewers prefer to use more delicate fermentation processes, including avoiding boiling the maple syrup, to retain the it’s unique flavor characteristics in the final product. This also reduces ingredient costs, since maple syrup can be expensive and should be used with care.

When making acerglyn (or maple mead), avoid boiling the maple syrup, and add it off-heat instead. When making maple beers and ales, use boiled and sterilized maple sap (instead of syrup) as the brewing water. Add maple syrup during secondary fermentation (rather than primary) to enhance the maple flavor.

Maple syrup is incredibly versatile for fermentation, but again, it’s best used as a flavoring agent rather than a primary sugar to save money and preserve the maple flavor.

maple tree with spigot for maple sap attached to metal bucket

What to Do if your Bottle of Maple Syrup has Fermented

If you have a bottle of maple syrup at home, and it has accidentally fermented, it may still be useful. Here are some tips for naturally fermented maple syrup.

First, smell it carefully. Store-bought, regulated maple syrup is usually processed to remove naturally occurring bacteria. Fermentation may be a sign that the maple syrup has been contaminated and should not be used.

In this instance, trust your nose. If it has a yeasty, beery smell that’s strong but not unpleasant, it’s probably still useful. If you see mold or discoloration, or if it has an unpleasant odor, throw it away.

Secondly, if it’s just a bottle of maple syrup that has fermented, you probably don’t have enough syrup to brew it into alcohol. Making acerglyn or maple beers and ales requires quite a lot of maple syrup. Instead, consider using it for the following:

  • If you are fermenting other items, maple syrup can make an excellent addition. Add fermented maple syrup to your homemade kombucha, apple cider vinegar, hot sauces, or chutneys. Fermented maple syrup has a complex, sweet flavor that enhances many other recipes.
  • If you place fermented maple syrup in an airtight container, add some vinegar mother, and allow it to ferment for several weeks or months, it will become a delicious maple vinegar. Maple vinegar is sweet and tart and an excellent addition to salad dressings, marinades, and other recipes.
  • If your bottle of maple syrup has a film on top and is mildly fermented, you may be able to simply save it. Skim the film off the top and pour the syrup into a pan. Gently heat it to 195° and allow it to simmer for 5-10 minutes. Then pour it into a new, sterilized container. Heating will kill the fermentation bacteria and will enable you to use the maple syrup as usual, provided that fermentation hasn’t progressed so much that it has severely affected the flavor.

In Summary

Maple tree sap is naturally sweet, so it’s understandable why people harvest and process it into maple syrup. It’s also makes perfect sense to process those same sugars into alcohol through the process of fermentation.

Maple syrup is an ingredient in a wide range of brewed and distilled alcoholic beverages, where it lends a natural, delicate caramel flavor. Maple syrup may also ferment naturally by itself, simply from the wild yeast in the environment.

If you have accidentally fermented maple syrup in the bottle, it can still be used to enhance all kinds of foods and recipes. And if you want to ferment maple syrup into acerglyn, maple ale or beer, or even maple wines and spirits, it’s another way to enhance flavors and create depth and dimension in your brews.