Member Highlight: Olmsted County — A sweet time at Oxbow Park

Below is a contribution from GMPT Member Olmsted County. For more information, please visit olmstedcounty.gov.

Maple “syruping” has been a North American tradition for hundreds of years. Native Americans started the tradition by tapping trees with wooden spiles and collecting sap with buckets made of birch bark. With the new advances we have today, you can purchase all the equipment you’d ever need at your neighborhood hardware or feed store.

The process is simple; you can even do it at home! Sap can be collected from a variety of trees within the “Acer” genus (maple and box elder). Sugar maples are the most common and efficient tree to use when collecting sap. For example, 35 gallons of sap collected from a sugar maple will produce one gallon of syrup. However, it takes a whopping 70 gallons of sap from a box elder tree to create the same amount of syrup. Sap begins to flow in late February to early March when daytime temperatures reach around 40 degrees Fahrenheit and nighttime temperatures are below freezing. The freeze-thaw cycle causes pressure changes in the tree, causing sap to flow. During the cold night, negative pressure in the tree causes the sap to rise to the buds to give energy to the tree. During the warm daytime, pressure becomes positive and releases the sap back down the tree toward the roots. This is when we catch the flowing sap in our spiles and collect the liquid in our buckets!

To begin the harvesting season, spiles are inserted 1 ½ – 2 inches into the tree’s cambium layer, catching the sap as it flows back to the roots. Sap is nearly 98% water and only 2% sugar. Once ample sap is collected, water needs to be boiled off to create the syrup. Boiling evaporates the water, leaving only the sugar. This can be done over a fire, woodstove, or in a DIY or commercial-grade evaporator. The sap is typically brought to a smaller finishing stove to finish boiling. Finally, the syrup is done when the temperature reaches 219 degrees Fahrenheit. A hydrometer can also be used to measure the syrup; it measures viscosity rather than temperature. Bottle your syrup, and voilà, it’s time for pancakes!

Oxbow Park staff and volunteers look forward to maple syrup season every year. It is a fun activity where everyone wants to participate. Thirty-two maple trees were tapped this 2025 season at Oxbow Park, producing around three and a half gallons of syrup. Many volunteers help by gathering the sap and boiling it in the evaporator. Thanks to very talented Olmsted County staff members, Oxbow Park uses a custom-made evaporator equipped to hold 80 gallons of sap. Naturalists and staff members host multiple public programming opportunities to teach the public about the maple syrup-making process. Programs are a hit and bring in many curious guests. The programs end with a sampling of fresh Oxbow Park syrup with vanilla ice cream. It is a “sweet” experience for all!