Sweet project: Biology students tap trees for maple syrup

St. Thomas biology students are making use of campus resources in a unique way.

Senior Albert Kertho, a biology major, tastes sap out of a freshly tapped tree while senior Zach Smith laughs in the background. (John Kruger/TommieMedia)

Twelve students in the biology department’s botany and plant physiology class have been tapping maple trees on campus for sap to make homemade maple syrup as part of a lab project.

“I had never done this before,” senior Albert Kertho said. “I grew up in Africa and there are no wintered trees.”

Kertho said they are trying to find differences in sugar content in the sap of different trees. Biology professor Amy Verhoeven said four kinds of maple trees were identified for the project: sugar, silver, Norway and box elder.

Students drilled a one- to two-inch hole in the side of the tree that received the most sun. Metal spiles, which are a type of spigot, were inserted into the trees to allow the sap to flow. The sap ran down a PVC pipe to a collection bucket.

“We are collecting samples throughout the week, and they (the students) are going to measure the sugar content of the different species and also changes over time,” Verhoeven said.

Greenhouse manager Steve Trost said his brother-in-law, a retired forester, visited campus to help locate the maple trees, because it is more difficult to identify the trees without the leaves.

“We marked them all with tape and then we contacted University Relations in case they got any calls from neighbors thinking we were going to remove the trees or anything,” Trost said.

Verhoeven said she is using this class project to illustrate biology concepts.

“We’re learning about transport in plants, so we’re learning about how water moves through from the roots through the tree to the leaves and how sugars are channeled through the plants,” she said.

Kertho said he was surprised about how much sap you can get from a single tree.

“I think in one tree we got about one gallon today, and then on Friday, [April 1], we will get another gallon,” he said. “So we’ll have approximately five gallons of each, and we’ll boil that down.”

Trost said it takes a lot of sap to make syrup.

“When we tap the tree, we need 40 gallons of sap to make one gallon of syrup,” he said.

The students will begin boiling down about 10 gallons of sap in the coming week.

“When we get it boiled down enough, we will bring in Eggo waffles, and we’re going to eat it,” Verhoeven said.

2 Replies to “Sweet project: Biology students tap trees for maple syrup”

  1. I know a priest in northern Minnesota that used to boil down the collected sap in the parish garage as part of a CYA/CYO fundraiser project. Nothing beats REAL maple syrup.

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