Maple Sugaring: The Sap Run

By Aaron Lefland, Forestry and Stewardship Coordinator

For decades, Land’s Sake has been continuing the New England tradition of turning the sweet sap of Sugar Maples into delicious maple syrup. Each year, we tap hundreds of trees, collect thousands of gallons of sap, and boil the sap in our evaporator to create syrup. This blog post will discuss the most important step in that process; the sap run.

Both volunteers and students in our after school maple program help collect sap

Both volunteers and students in our after school maple program help collect sap

When does the sap start to flow?

Anyone who has been involved in the maple sugaring process knows that things are basically stagnant until the sap starts to flow (pardon our pun). This year has been an exceptionally cold winter, meaning that the sweet sap of the Sugar Maples is frozen in the trees and has not been running out of the taps we installed. Fortunately, things are starting to warm up, the trees are thawing out, and our precious sap will slowly start dripping out of the spiles and into our buckets. Once we consistently have days with temperatures in the low 40s, our buckets will start to fill and the sap will  be brought to the sugar shack and boiled down.

What causes the sap to flow?

According to Cornell’s Sugar Maple Research and Extension Program, “during warm periods when temperatures rise above freezing, pressure (also called positive pressure) develops in the tree. This pressure causes the sap to flow out of the tree through a wound or tap hole. During cooler periods when temperatures fall below freezing, suction (also called negative pressure) develops, drawing water into the tree through the roots. This replenishes the sap in the tree, allowing it to flow again during the next warm period. Although sap generally flows during the day when temperatures are warm, it has been known to flow at night if temperatures remain above freezing.” Read more about the process HERE.

How fast does the sap flow?

When a good run is underway, sap drips out of the spile a little more than once per second. Many people say that a steady sap drip should be similar to the rate of a resting heartbeat. Although this may seem pretty slow, a good run can necessitate a full collection every day. We  try not to waste time collecting buckets before they are full, but need to be equally as careful not to let them overflow and waste sap. Fortunately we have a great group of volunteers that help us collect sap, and you can join us in this process by subscribing to our email list below.

Although only about 2% sugar, buckets of sap can provide a sweet, refreshing drink while collecting.

Although only about 2% sugar, buckets of sap can provide a sweet, refreshing drink while collecting.

When does the sap stop flowing?

If we were to leave our spiles in the tree, they would theoretically keep dripping sap until the tree began to heal after a few months. So why do we stop collecting the sap? It turns out that there is a chemical change in the composition of the sap that occurs once the buds on the trees start to pop. “Buddy sap” as it is affectionately known, can still be safely boiled down to make syrup, but has an off-flavor that most people do not enjoy. Unfortunately, it is difficult to predict exactly when the buds will pop, so we collect as much syrup as we can in the limited window that nature gives us.

Want to get involved?

If you are interested in volunteering to collect sap, help with the boiling process, or do anything else maple-related, please join our maple-specific email list HERE. As the sap flow begins, we will need all hands on deck to help collect the hundreds of buckets we have hung with the help of our volunteers and after school group.

 

Posted in Maple.