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Researchers extract sap from maple saplings

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Smaller maple trees could be used to produce syrup with a new system being researched in Vermont. Photo by Bethany M. Dunbar
Smaller maple trees could be used to produce syrup with a new system being researched in Vermont. Photo by Bethany M. Dunbar

by Tena Starr

copyright the Chronicle 11-27-2013

Researchers at the Proctor Maple Research Center have stumbled onto a new way of sugaring that could revolutionize the most rapidly growing agricultural industry in Vermont.

Instead of getting 100 taps per acre, it would be possible to get 5,000 or more.  Instead of getting roughly 40 gallons of maple syrup per acre, it would be possible to get as much as 400 gallons per acre.

It would be possible, in other words, to have a prosperous sugaring operation on a single acre of farmland.

The idea is that saplings could be “tapped,” either in a regenerating sugarbush, or in a densely planted field.

Four years ago, Tim Perkins and Abby van den Berg at the Proctor Maple Research Center set out to study how sap flows in maple trees when a vacuum system is employed.  Vacuum sucks sap out of a tree rather than letting it flow at its natural, and much less predictable, rate.

Normally, in a thaw, sap flows downward through the tree.

“But if you’re on vacuum, you continue to get sap out of a tree after that process stops,” Mr. Perkins said.  “The only logical conclusion was that we were pulling sap up out of the ground.”

If that’s the case, then the top of the tree isn’t necessary to get a sap run, Mr. Perkins noted.  So, to test the theory, he and Ms. van den Berg lopped the top off a sapling, attached a plastic bag with a piece of tubing to the top of the stump, and sucked the sap out with vacuum.

It worked.  It worked so well, in fact, that, after four years of research, Mr. Perkins has concluded they discovered a whole new way of making syrup — one that could protect the industry from climate change and Asian longhorned beetles, allow new sugarmakers to get into the business despite prohibitively high land prices, and permit existing operations to expand.

A new sugarmaker could plant a closely spaced plantation of maple saplings.  A sugarmaker already in business could end up “tapping” the saplings that have grown up in his woods instead of clearing them out.

“There’s no question it works,” Mr. Perkins said.  “We generally don’t like to talk about things unless we know they’re going to work.  We spent four years looking at this before we began talking.  You can certainly make considerably more syrup per acre than with the standard method of sugaring.”

The only problem is it’s not yet possible to sugar such a plantation.  That’s because the device needed to get sap out of a sapling doesn’t exist — at least not on a large scale.

Mr. Perkins said the researchers made the equipment they used by hand, but no one would want to make enough for an entire plantation.  “It’s the same as if you had to whittle your own spouts,” he said.  “You wouldn’t want to make 5,000 or 6,000 of them.”

The device that’s missing is the plastic bag with the piece of tubing that would connect to the rest of the system.  “You need to get that sap out of the bag,” Mr. Perkins said.  “You can’t do it now because the devices to pull out the sap aren’t available commercially.”

Manufacturers have been approached and expressed interest, but at the moment no one is producing the piece needed for such a sugaring operation, Mr. Perkins said.

“We’ve spoken to manufacturers very briefly,” he said.  “Our next step is to start meeting with each manufacturer, describing it in more detail, and seeing if they want to start working with us.”

Among longtime sugarmakers, the procedure has generated good-natured cautiousness.

“When I saw it my immediate opinion was that’s crazy,” said Bucky Shelton of Glover, who has sugared for 35 years and is a sales and service man for Lapierre USA in Orleans.  “But if you put your mind into the future then it’s probably an interesting way to do this.  I’ll say one thing, you don’t have to worry about the wind blowing them down.  “It’s more secure as far as environmental problems go.”

Wind is a major threat to sugarmakers, and storms have been increasing, Mr. Shelton said.  He’s still cleaning up his own sugarbush, which was hit by a windstorm in May.

Jacques Couture, chairman of the Vermont Maple Sugarmakers Association, also a longtime sugarmaker, agrees that plantation sugaring could be a defense against increasing threats.  For instance, the hurricane of 1938 wiped out many mature sugarbushes, setting the business back years, he said.

“Some of the older sugarmakers talked about that.  All these beautiful sugarbushes got completely mowed down.”

“I don’t see myself doing it anytime soon, but it’s interesting,” Mr. Couture said.  “If we had some kind of major disaster, a lot of people would look at this seriously.”

That’s one of Mr. Perkins’ points.  Vermont’s sugaring industry, thriving right now, is whim to weather and pests, as is any agricultural venture.

The Asian longhorned beetle isn’t yet in Vermont, but it’s been found in neighboring states, and currently there are infestations in Massachusetts, New York, and Ohio.  It’s a serious threat to maples and other hardwood species, but it doesn’t like little trees, Mr. Perkins said.  They’re big beetles, and they like big trees to bore into, he said.  Saplings just don’t appeal to them.

And, 50 years down the road, as the temperature warms, smaller maples will be more likely to produce syrup.  Being smaller, they freeze and thaw quicker, allowing for more sap runs.

“In the projected environment we’re going to have 50 years from now, smaller trees will probably be better suited for sugaring,” Mr. Perkins said.

The ideal maple for plantation sugaring would actually look more like a bush than a stately 100-year-old maple.  Two-inch stems are optimum, Mr. Perkins said.  A single stem works fine — for a while.

The first year the top would be cut off to get the sap run.  Each year another six to 12 inches would be cut off the top of the stem to get the sap running.  But with a single stem, “eventually, you’re going to get to ground,” Mr. Perkins said.  A sapling with multiple stems, on the other hand, could last a very long time.

At the moment, the cost of production, for a variety of reasons, works out about the same as for a traditional sugarbush, Mr. Perkins said.

“Where this new method starts to get better is if you can plant saplings that have the genetics to be sweet trees,” he said.

And work has been done on developing particularly sweet varieties of maples, Mr. Perkins said.  Individual trees vary in sugar content, he said, and researchers were breeding for sweetness.  That work came to an end when reverse osmosis was introduced, he said.  Reverse osmosis removes some of the water from sap before it’s boiled, thus “sweetening” it and reducing boiling time.

“If we can increase the sugar content of sap to 3 percent, you’d go from 400 gallons an acre to 600 gallons,” Mr. Perkins said.

A plantation of particularly sweet trees would significantly cut the cost of production.  “If we could breed sweet trees and grow them fairly quickly,” the economics would be quite different, Mr. Perkins said.

The cost, and availability, of land is also a factor in sugaring today, he said.  “In Vermont right now about 50 percent of the optimal land for sugarbushes is being used for sugarbushes,” he said.  “The rest of it is mostly tied up.  There’s still land available, but it may not have the highest density, or people don’t want sugaring there.  This provides another option for people to continue to grow their operation.”

The idea of plantation sugaring, turning what is currently a semi-wild crop into a farm crop, causes some sugarmakers to raise an eyebrow — and laugh a little.

“It’s not too romantic,” Mr. Shelton said.  “One of my first thoughts was, boy, this is pretty far from tradition.”

“It does change the image if it becomes a cornfield type of thing, or sugarcane type of thing,” Mr. Couture said.

No, cutting the tops off saplings is not a traditional notion of sugaring, Mr. Perkins said.  “But, unfortunately, the traditional image doesn’t represent the reality of what’s out there.  We don’t have people walking around with horses anymore.”

He said he doesn’t see the new way of sugaring replacing the traditional methods anytime soon, although it could augment some operations and buffer the entire industry against disaster.

So far, the reaction from sugarmakers has been generally positive, Mr. Perkins said.

“I’m definitely open to seeing how it works,” Mr. Shelton said.  “They’re thinking out of the box, and I think we need to think out of the box for the future.  Everything old school is just getting uprooted.  It’s important to be thinking in these terms.”

Steve Wheeler at Jed’s Maple in Derby, which produces organic syrup and maple products, said he had not yet even heard about sugaring maple saplings.  “We’re set up so traditionally here that it’s kind of a shock,” he said.

He said he hasn’t formed an opinion, but sees no reason why sugaring in a whole new way wouldn’t work.  “I don’t see why you can’t approach it like traditional farming.”

Mr. Wheeler said he has great respect for the UVM researchers.  “Proctor has some really neat ideas,” he said.

contact Tena Starr at [email protected].  For more free stories like this one, see our editor’s pick category on this site.  We hope these will interest you enough to make you want to subscribe to our online or print editions.

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