Local pancake lovers tapped the University’s maple syrup source last weekend at the Minnesota Landscape Arboretum’s 14th annual Sugarbush Brunch and Maple Tour.
Erratic spring temperatures have stunted the year’s maple syrup harvest, but the arboretum’s 50-gallon batch of home-grown sweetened sap was ample enough to feed 3,200 hungry mouths.
“The brunch is born out of the idea that we tap the sap,” said Lori Carsik, the arboretum’s public relations director.
The public ate the spoils, then toured the Sugarbush — the arboretum’s maple stands, sugar house and history room — to see how sap slipped from the trees to their breakfast plates.
The three-part tour gave visitors the full syrup experience; from historical use to which trees are tapped and how sap is boiled into a final product.
“It’s a chance for people to connect with the rhythms of the seasons and enjoy a sweet goodbye to winter,” said Sandy Tanck, who directs youth and teacher education.
The University-supported arboretum is located in Chanhassen, a Dakota name for the place where sugar maple sap is gathered. Dakota people traditionally returned to this area each season to harvest sap for maple sugar.
Arboretum staff and volunteers explained how to harvest sap, a technique that hasn’t changed much over time.
Trees at least 10 inches in diameter are bored two inches deep, then plugged with a hollow metal spike, or spile. Sap drips from these spiles into bags or through a tubing network which leads the clear, sweet water down a slope to an arboretum holding tank.
Each year 150 trees are tapped and tubed while another 100 drip into bags. One tap sucks about 10 gallons from the thousands that flow up and down a tree during a season.
Sugar maples are uniquely high in sugar sap content. Their sap consists of 2 to 4 percent sugar, depending on the tree. The remaining sap is water. Once collected, the sap is boiled down in the arboretum’s sugar house.
“Sap minus water equals syrup,” volunteer instructor Paul Schick told visitors as a gas-fired, gravity-set cooker boiled sap down to a 66.5 percent sugar content. A higher sugar ratio crystallizes the syrup, but a lower one fails to meet pure maple syrup standards.
It typically takes about 40 gallons of sap to make one gallon of maple syrup. The arboretum has a sweet 30-to-1 ratio.
Officials don’t know if it’s the El Nino effect, but warm weather has made an unpredictable season even more uncertain, said maple harvesters Matt Schuth and Carl Vogt.
Sugar maples are typically tapped between March and mid-April, when a combination of below freezing nights and above freezing days stimulate sap flow. Little happens without these conditions.
Schuth said unless freezing temperatures return soon, the season will end with half of the arboretum’s normal 3,000-gallon sap harvest.
Weather patterns this year have been intense, said Vogt, a University forestry professor. And the next couple days are crucial to an abundant harvest.
The two- to eight-week season ends when buds form on trees, because sap turns milky and loses its sweet flavor.
Minnesota makes 10,000 gallons of syrup a year. “A drop in the bucket of maple syrup production,” said Vogt, who is also treasurer of the North American Syrup Council. Vermont leads the nation with 500,000 gallons. Canada supplies 80 percent of the world’s pure syrup.