A shiny wood-pellet-fired evaporator dominates the view from the doorway of the sugar house at Tucker Mountain Maple. But on a mid-March day, certain to be a good day for boiling, the evaporator stands cold, and Eric Johnson and his helpers Sophie Viandier and Peter Southworth are trying to solve a mystery. What is the cause of the musty-smelling sap? Is it the membrane in the reverse osmosis machine? Or maybe something in the bulk tank?

Every 30 minutes when the system is running, pellets are automatically fed from the outside silo to this square feed bin.

Eric Johnson, a former logger and high school teacher who has worked with many farmers and timber owners on forest stand improvement, long dreamed of making maple syrup. He turned a small building on his Andover, New Hampshire, land into a sugar shack, purchased a wood-fired evaporator, and in 2005 made his first Tucker Mountain Maple syrup. He used the wood-fired evaporator until 2013, the year following his 2012 diagnosis of amyotrophic lateral sclerosis, a neurological disorder also known as Lou Gehrig’s disease.

Choosing pellets

To help continue his passion for sugaring and to ease its physical demands, Johnson replaced his wood-fired evaporator with a wood-pellet evaporator. As one who works in forestry, Johnson did not consider oil-fueled equipment. In 2014 Johnson purchased his evaporator manufactured by CDL of Saint-Lazare, Quebec, and distributed by CDL of St. Albans, Vermont. The 2.5- by 8-foot evaporator is fitted with high output raised flue pans made by Smoky Lake Maple Products of Hilbert, Wisconsin. Smoky Lake handmakes evaporator pans, which it advertises as being “incredibly efficient and intelligently designed.” The system is rated for 80 gallons of evaporation an hour. “The entire wood pellet system with pans,” Johnson said, “cost about the same as a new Subaru Outback.”

Running Tucker Mountain Maple’s original wood-fueled system took about 10 cords of firewood a year. At $300 a cord for dry firewood, Johnson calculates the cost of fuel to make one gallon of maple syrup using his original wood-fueled system was $2.50 per gallon. The $2.50-per-gallon figure includes the cost of labor to stack and handle the firewood. Johnson figures the cost of making one gallon of syrup using wood pellets is $2. Pellets are delivered into a silo from which they are automatically fed to the evaporator. “Six and a half tons of pellets now do what 10 cords of wood did previously,” Johnson said.

A renovated building houses Tucker Mountain Maple’s wood-pellet-fueled evaporator. A silo behind the sugarhouse holds 6.5 tons of wood pellets. Sophie Viandier (in the doorway) is one of many devoted friends and family who helps Eric Johnson continue his passion for sugaring.

How the wood pellet system works

The system’s silo is filled with 6.5 tons of pellets produced by New England Wood Pellet of Jaffrey, New Hampshire. Every 30 minutes when the system is running, an auger automatically brings enough pellets from the outdoor silo to fill the square feed bin adjacent to the evaporator. From the bin, a 6 rpm auger within a long black tube brings pellets from the bin to the firebox at the far end of the evaporator. A propane torch is used to ignite the pellets. Pellets burning in the firebox reach a temperature of 1,500 to 2,000 degrees Fahrenheit. Gases exit the stack at about 800 degrees Fahrenheit. Operating the system for one hour takes 100 pounds of pellets. By comparison, a residential wood pellet heating system burns about 40 pounds of pellets a day.

With the Lapierre reverse osmosis machine running, the wood pellet evaporator, rated for 80 gallons of evaporation per hour, can make five to seven gallons of syrup per hour. The RO machine, a turbo model rated at 600 gallons per hour, processes an average of 450 gallons of sap an hour.

Pellets are stored in this silo which holds 6.5 tons of pellets.

From sap to syrup

At the peak of its 10-year-long operation, Tucker Mountain Maple had 1,400 taps – 1,200 on tubing and 200 on buckets located on some 20 properties around the town of Andover. “In Merrimack County, New Hampshire, in which Andover is located, only 1 percent of all species of trees is sugar maple,” Johnson said. Owners of bucketed trees are paid in syrup at the rate of one pint per six taps. In addition to the sap it collects, Tucker Mountain purchases and processes about 20,000 gallons from another producer.

This year, when Johnson was no longer able to do woods work, family and friends put in taps, 700 on tubing and 40 on buckets. IPL tubing is used for laterals and black water tubing for main lines. All tubing is semi-rigid, and all lines are vacuum. Vacuum has also made it possible to utilize red maple trees. Now, 20 percent of taps are red maple and 80 percent sugar maple. “Our biggest sugarbush is 425 taps, almost too small to have vacuum,” Johnson said, “but vacuum has increased yield so that it is worth it.”

Back of “Got sap?” sweatshirt.

At every sugarbush, sap is collected in bulk storage tanks calculated to hold two gallons of storage per tap. Sap is then transported by pickup truck to a stainless steel 3,000-gallon tank at the sugarhouse. None of the lines runs into the sugarhouse.

Johnson takes sap to 12 percent concentrate. In 2014, the sap to syrup ratio was 43:1.

The best year’s average was 32:1 in 2011.

Keith Johnson sports the “Got sap?” sweatshirt his brother Eric designed.


In plastic jugs, fancy glass bottles, and in sizes from half pints up to gallons, all Tucker Mountain retail sales are from its Andover location. In 2014, retail (including shipped syrup) accounted for 50 percent of sales while 20 percent was wholesaled to three accounts and 20 percent was in bulk sales. The Johnsons make maple cream for holiday sales. A local sugarmaker makes maple candy in return for very dark syrup.

“I have always admired businesses that contribute to good causes,” Johnson said. In that spirit, Johnson gives away about $2,000 a year in syrup. Recipients are local fundraising efforts and especially an organization called Compassionate Care ALS. Compassionate Care ALS is an organization that supports people and families of people with ALS. Last summer’s Tucker Mountain Maple Ice Bucket Challenge – using maple sap buckets – also benefited Compassionate Care ALS.

Eric Johnson, selfproclaimed Master of Ceremonies, working with Sophie Viandier and his brother Keith Johnson to try to solve the mystery of the musty sap.

Passion unchanged

“ALS has changed my abilities, not my passion for making maple syrup,” Johnson said. Dubbing himself Tucker Mountain Maple’s Master of Ceremonies, Johnson patiently instructs family and friends in the fine art of sugaring. Brother Keith, who comes every weekend from Cape Cod, a four-hour drive, sports a sweatshirt designed by Johnson. On the front left: “Got sap?” On the back:


“Hi, my name is __________________. It’s been ___ days since I’ve been in my sugarhouse.”

Johnson is 45. While grateful and humbled by all the help of family and friends, Johnson predicts that 2015 will be the 10th and last year Tucker Mountain Maple makes syrup. As for the musty sap mystery: The culprit appears to have been the bulk tank that may not have been thoroughly cleaned last season. The tank held 1,500 gallons of sap, and it all had to be dumped.

Cover and Photos by Kathleen Hatt