By Tina Snell, Staff Writer
It’s maple syrup time. At least, it should be. This year, winter is hanging on longer than usual. But, as daytime weather warms and nights stay cold, the sap will be running soon.
The Krolls are ready. About 1,500 taps have been put in many of the maples on the Kroll property.
The farm, just east of Long Prairie, has been in the maple syrup business for about 53 years. It was originally settled by Hans Kroll’s great-great-grandparents, the Heincks.
“My dad, John Kroll, started making maple syrup when I was about 6 years old and he still is a big part of the process,” said Kroll.
Kroll said the first syrup house was just a shack.
We started making syrup just for ourselves. We would place several hundred taps and use large tin bakery boxes to collect the sap,” he said.
In about the 1960s, the tins were replaced by thick plastic bags. From those, the Krolls graduated to disposable plastic bags, which they use today.
More contemporary operations use vacuum pumps to get more sap from the trees, but the Krolls still let the sap run at its own pace.
Beginning in about February or March, depending on how many trees are going to be tapped, Hans locates the maples which are at least 12 inches in diameter. Those get one tap. A tree that is 18 inches in diameters can have two taps.
A 7/16-inch bit is used to drill a two-inch deep hole in the maple. The tap, a metal tool that guides the sap to the waiting container, is then snuggly fitted into the hole.
The science behind sap running is complicated, but Kroll said the weather needs to be cold at night and warmer during the day to optimize the flow.
“When the air temperature is below freezing, the tree’s capillaries contract, which draws the sap upward. When the weather warms, the capillaries expand and the sap descends. When the pressure inside the tree is greater than outside, the sap will flow out the tap,” he said.
The sap will flow at different rates, depending on the temperature. One tree can give up to three gallons of sap a day.
The taps on each tree are never in the same spot. Each spring, the holes are drilled approximately six inches to the side of the previous year’s tap and about three inches up.
“The scarred spot is stronger than other parts of the tree and the sap doesn’t run as well,” he said.
“If the weather suddenly turns cold, the sap will stop running, but will start up again when it warms,” said Kroll, who goes out almost daily to check the progress.
“A run can last from a week to a month,” he said.
All the Krolls are part of collecting the syrup. John, Hans, Thomas, Hans’ daughter Leah Murtha and her children all help out.
Hans’ son Thomas said he loves collecting; he loves being in the woods.
The family dumps the sap into five-gallon buckets, then transfers it to collecting tanks being pulled on a trailer through the woods. The sap is brought to the cook house where it’s pumped into a holding tank above the cooker.
“The sap will enter the gravity-fed cooker through pipes that preheat it. The sap runs through the cooker’s chambers, boiling at about 219 degrees,” said Kroll. “In the last chamber, the syrup is then drawn off into containers, being filtered as it enters.”
The entire cooking process takes about six hours.
When the sap leaves the maple tree, it has about a 2 percent sugar content. It is clear and not sticky. Water from the sap needs to evaporate for it to reach a density of 67 percent sugar.
As the sap cooks down, the color changes from clear to the amber color people associate with syrup. The cooking process gives the syrup it’s color, body and taste.
The sap is about 98 percent water when it leaves the tree. The syrup is about 33 percent water.
“To ensure we have the correct amount of sugar in the syrup, we use a refractometer, which measures the sugar content with light and prisms,” said Kroll. A refractometer will measure how the light is refracted in the syrup. The higher the sugar concentration, the more the refraction.
If the Krolls collect 430 gallons of sap at a 2 percent sugar density, the family will produce 10 gallons of syrup. They have collected enough sap in past years to make more than 600 gallons of syrup.
Two of Kroll’s grandchildren, Brennan and Delaine Murtha, said the best part of the entire process is tasting the syrup as it comes out of the cooker. With mugs and spoons in hand, they blow on the hot syrup until it’s cool enough to sample.
In addition to producing maple syrup, the Krolls operate an organic dairy farm.