It’s a sweet time of year

BARK RIVER – Despite a bitterly cold and seemingly endless winter causing a late start to the season, maple syrup production seems to be on track in the Upper Peninsula.

“If I ignore the calendar it’s not too bad,” said Jeff Olson who owns Olson Bros. Sugar Bush in Bark River with his brothers Greg and Mark.

According to Olson, the season is roughly 15 days behind where it would typically be this time of year. However, as long as temperatures rise gradually, allowing a freezing and thawing pattern to develop, this spring’s syrup production should be on par with other years.

Ideally, sap should be collected when temperatures fluctuate between the 20s at night and the 40s during the day. This causes the natural gases inside a maple tree to expand and contract pushing the sap towards the area of the tree with the least pressure – the tap.

“I tell people a frosty windshield in the morning is an indicator of a good sap run day,” said Olson.

The freezing and thawing cycle is also important because it keeps the tree from passing the point when the harvesting season must end.

It postpones the tree from budding a little, according to Jeff Jasper of Jasper’s Sugar Bush in Carney.

If the weather stays above freezing consistently the trees will begin to bud. Besides slowing down the rate that the sap “runs” at, the budding process changes the composition of the sap. Syrup made from the sap of a budded tree is bitter.

“It wouldn’t be table grade syrup,” said Olson.

Until the budding process begins Olson Bros. will continue to run their roughly 10,500 taps, which are attached to vacuum pumps to keep the sap flowing down the line and increase production.

Typically, about 40 gallons of sap is needed to make a single gallon of pure maple syrup. However cold weather and snow cover preventing the roots of trees from warming is causing more sap to be needed for some maple syrup producers.

“Instead of taking 40 gallons it’s taking 60-65 to make a gallon of syrup,” said Jasper.

“Once the roots get some heat in them, hopefully the amount of sap it takes to make a gallon will be less,” he added.

At Olson Bros. the raw sap is run through a special reverse osmosis system that uses a high pressure pump to force water out of the sap through a membrane. Using the system 1,000 gallons of raw sap creates 200 gallons of condensed sap that can be boiled down further to reduce the water content and produce maple syrup.

“As you can imagine that dramatically reduces the amount of firewood we need,” said Olson, adding that without the reverse osmosis system the six-foot by eighteen-foot, chip operated boiling system used to evaporate sap and create syrup would require roughly 250 cords of wood to operate for the season. With the reverse osmosis system only 50 cords are needed to evaporate the condensed sap.

The sap is boiled until it reaches 66 brix – a unit of sugar density that represents the strength of the solution as a percentage by weight. At that density the sap has officially become syrup by Michigan Maple Syrup Association standards.

While the season seems to be on track, Olson did express concern over the possibility of a sudden warm up causing budding and creating a short tapping season. However, because maple trees farther south in the Sheboygan, Wis., area have not yet budded he does not expect budding to happen immediately on the trees this far north.

“I’m glad that we’re farther north,” he said, adding that maple syrup producers in the Lansing area who just began tapping trees would probably experience a shorter season.

For Jasper, the season has just started and very little syrup has been produced. He believes that it is too soon to tell how the season will pan out for harvesting.

“Another week or so will really tell a lot,” he said.