LONG EDDY, NY — Above the red sap house, the plume of white, sweet-smelling steam was fleeting—rushed into nothingness by the late-winter day’s dry air.

On damper days the vapor lingers, spreading sweetness throughout the valley and the sugar maple forest on the mountain above Andersen’s Maple Farm.

It was here in 1936 that August Peter Andersen began collecting sap in buckets and boiling it to make maple syrup in a wood-fired evaporator down in the forest. He was an urban contractor from Denmark who knew next to nothing about farming, said Irene Andersen, who married August’s son, August Erik Andersen.

“He lost everything in the Great Depression. He started looking for land because he couldn’t eat the sidewalks,” Irene said of her father-in-law.

Her son Peter now runs the 1,000-acre multi-purpose farm, which has become the largest producer of maple syrup in the region. It is located in “Rock Valley,” a name given by locals because digging with a shovel around here is more likely to produce sparks than dark soil.

If at local farmers markets you’ve seen the maple leaf-shaped glass bottles colored medium amber by the sweet, yet delicate syrup, you’ve glanced at the tail end of a process that begins the day after Christmas every year when Peter starts installing about 8,000 taps in the sap bushes, or groups of sugar maple trees. Each bush bears its own name.

The taps feed a maze of lines that all lead to the sap house below the mountain.

“We don’t use any buckets anymore,” Peter said. Modern equipment has enabled the family to maximize the farm’s potential and ensure quality for their maple sugar products, which they distribute throughout the Delaware and Hudson River valleys and Finger Lakes region, often through local farmers markets. Still, Peter only taps each tree once a year; each hole lasts for about six weeks.

In order for the sap to run, it has to freeze at night and thaw fairly rapidly during the following day. The ideal temperature fluctuation between night and day is about 20 to 50 degrees.

It was just above 40 degrees on Saturday, March 19 and the sap was running but not killing itself, said Peter, a Cornell University graduate. After drawing the boiled product from the finishing pan, Irene poured the hot, medium-grade syrup into glass bottles with help from Peter’s daughter Megan.

“This is the old-fashioned way of filling bottles,” Irene joked.

The clear sap from about 3,000 taps was filling a holding tank at a rate of about 1,000 gallons per half-hour. Raw sap consists of only about two-percent sugar, and the processes of filtering and boiling increase the concentration to about 66 percent sugar, Peter said.

The sap is pumped out of the holding tank and through reverse-osmosis (RO) machines that separate sugar molecules from water molecules under high pressure. Then ultra-violet lights kill bacteria. After the sap passes through the RO filters, it contains about eight percent sugar.

Then in large, stainless steel oil-fired evaporators, 70 percent of the water remaining in the sap is boiled off at about 217 degrees Fahrenheit. The reduced liquid is pumped into the finishing pan, about 10 gallons at a time. Peter checks the density with a hydrometer—which gauges temperature—in order to ensure that each batch matches the medium grade he is looking for.

Forty gallons of sap (at two percent sugar) makes about one gallon of finished maple syrup. Peter grosses about a quart of syrup per tap, per year.

Most other maple sugaring farms in the region are small, according to Ed Pruss of Penn State Cooperative Extension in Wayne County. Pruss said that regionally, producing maple syrup is mostly something farmers do while their fields are drying out.

“For dairymen it is a good source of supplemental income,” he said.

Margaret Simons of west Damascus, PA, a teacher at Honesdale High School, started boiling sap in the 1980s as a hobby. She hopes to grow her output over the next decade, but Simons also views maple sugaring as a threatened way of life. Its preservation has become a cause worth fighting for in the face of global climate change.

On behalf of the Northeast Maple Producers’ Association, Simons wrote a letter in early February to Pennsylvania senators Arlen Specter and Rick Santorum, urging them to take climate change seriously for the sake of the maple industry in the Northeast.

“Recent climate models show that our maple/beech/birch forests will be completely displaced by more southern forest types by the end of the 21st century. Maples are expected to die out in the northeast U.S., except for isolated high elevation sites,” Simons wrote.

Asked about the assertion, Dr. Stephen Childs, a maple extension specialist at Cornell University, said, “It isn’t anything that we see happening. They’re [Northeast Maple Producers’ Association] trying to get a situation remedied before it becomes a reality.”

Peter Andersen said the seasons have shifted slightly, though his fear of the destructive traits of forest tent caterpillars factors much more prominently in his mind. The forest tents have a 40-year cycle and can decimate entire maple forests when they hatch.

Around 1990, the caterpillars caused a “tremendous defoliation” at Andersen’s Maple Farm, Peter said. That’s a major problem because fewer leaves flourishing in a sap bush’s crown mean less sap production.

For now, it’s springtime business as usual at the farm.

National forecasts predicted perfect weather for drawing sap through April 1, according to Dr. Childs.

[Andersen’s is still in business in 2015; call 845/887-4817 or email maple5@localnet.com. For a 2015 guide to local maple syrup producers, visit tinyurl.com/k7u4rp5. See also the self-guided tour described on page 27.]