Off Flavors and Their Causes

  1. “Buddy” Flavor3

    When the buds appear on the maple trees, it’s our signal to stop collecting sap from the trees. Failing to do so will result in syrup that has what is called a “Buddy” flavor. This has sometimes been described as having a Tootsie Roll flavor.

  2. Earthy or Woody

    This flavor can manifest if new tap holes are too close to old tap holes. Stay at least 10 inches above or below old tap holes and at least 2 inches to the left of right. Also, never tap unhealthy/punky sections of a tree.

  3. Fermented

    If syrup is not boiled long enough (less than 66º Brix), it may start to ferment in the container. It will taste “spiked”. Taste like alcohol but not in a good way.

  4. Chemical

    If equipment is not thoroughly rinsed, the taste of soaps and detergent may appear in your syrup. Never use soap to clean cone filters or flat filters. Residues from soaps will remain in the fibers and cause off flavors the next time you use the filter.

  5. Defoamer

    While boiling, foam will form on top of the sap. The foam can be controlled by periodically putting ONE drop — or even a fraction of a drop — in the pan. However, if too much defoamer is used, an off flavor and oily texture may arise. Use a very neutral-flavored oil — such as canola oil — as your defoamer. Using things like butter and bacon grease to control the foam are strongly discouraged.

  6. Burned Flavor

    This can happen when there is too much sugar sand build-up on the floor of your pan. Keep your equipment clean. This flavor can also arise if your pan was previously scorched and there is still some charred sugar stuck to the pan.

  7. Plastic

    If maple syrup is packaged in food grade plastic containers for a long period of time, it may take on a plastic tone in the flavor. Ideally, maple syrup should not be stored in plastic for more than 3 months. (See our article “Plastic Vs Glass”)

For more information about unpleasant off flavors and their causes, please check out the resources below! The Vermont Maple Association also sells reference bottle sets to help you identify off flavors and their causes.

Flavor Wheel

Flavor Wheel by ACER Centre, Canada2

Flavor Map by University of Vermont

Flavor Map by University of Vermont1

References and Resources

  1. “Final Report Marketing the Taste of Place: The Case of Vermont Maple Syrup”, Dr. Amy Trubek FSMIP, work cited online on 6-4-19.
  2. “Flavour Wheel for Maple Products”, Acer Centre, Canada, work cited online on 6-4-19.

  3. “Off-flavor syrup reference available. Kit intended for anyone who works with pure maple syrup.”, By Mark L. Isselhardt, Maple Specialist, University of Vermont Extension, Article dated February 2017, work cited online on 6-4-19.

  4. “How to Identify Maple Syrup Off Flavors”, By Henry Marckres, The Maple News, April 2019, work cited online on 6-4-19.