On a snowy slope in Underhill Center, Vt., just down the road from UVM’s Proctor Maple Research Center, Professor Abby van den Berg ducks under some pale blue tubing that runs through the forest.

“Here are some of our trees,” she says with a hint of a smile.

It’s conventional plastic tubing used in the maple syrup business. Each stretch is connected to a black spout sticking out of the side of a tree. Then the chest-high tubes run gently downhill, pulling sap, under vacuum pressure, to collecting tanks. Everything here looks like a modern maple sugarbush.

Except the trees. They’re not maples. They’re birches. “It’s odd, isn’t it?” she says.

Up a long dirt driveway, off Route Seven, in Leicester, Vt., Kevin New and his cousin have converted an old goat barn into a sugarhouse. “As you can see, we don’t win awards for the looks of our shack,” he says, laughing, “but we have won awards for our maple syrup.” A sweet steam rises off the evaporator pan and he runs a skimmer through boiling sap. Along one wall he’s tacked a pair of blue ribbons from the Addison County Fair. Against the back window, stand two neat rows of mason jars filled with rich reddish syrup.

Except the syrup isn’t maple syrup. It’s birch syrup.

These may be the only two places in Vermont where birch sap is being made into syrup.

“I heard though Facebook that there is a guy up in Franklin County who was going to try it,” New says, looking out the window, “but as far I know I’m the first one.”

What’s in birch?

If Abby van den Berg’s new research project in Underhill comes back with promising results, she expects to see more Vermont maple sugarmakers adding birch syrup production into their business.

In March, van den Berg and her colleagues at the Proctor Center, Tim Perkins and Marc Isselhardt, and her work-study student, Teague Henkle ’14, tapped 40 birch trees in five research plots at the Proctor Center. It’s an experiment funded by the Northeastern States Research Cooperative. They’re not actually going to make much of the sap into syrup; just enough to make sure it tastes good. What they really want is data on how much sap — and sugar — birch trees produce.

“We want to see whether there is enough sugar produced by birches here in Vermont, using modern tools and techniques — like vacuum and reverse osmosis — to make a profitable addition to an established maple operation,” she says.

But to do that economic analysis, van den Berg first needs to figure out some birch basics.

“We don’t know a lot about birch here in the Northeast,” she says, “How long is the season? How much sap do different size trees make? How much sugar will they yield? How many trees and taps would you need to be profitable?”

What’s it worth?

Kevin New is asking himself the same questions and he’s talked with van den Berg on the phone about what they’re both learning.

Birch sap is more watery than maple sap. Typically, forty to sixty gallons of maple sap yields one gallon of syrup. For birch sap, it’s well over a hundred gallons to one. “I’m averaging 116 gallons of sap to make a gallon of syrup,” New says.

This adds a tremendous amount of fuel and time to the syrup-making equation — which is one of the reasons birch syrup is rare. There are four commercial producers in Alaska, a few in British Columbia and other parts of Canada and one established maker in New Hampshire.

But the other side of the scale is this: Alaskan birch syrup is now selling for $78 per quart. One major producer there sells gallons for $328. New is testing his prices at $50 per quart.

“Is it worth it? Will people buy it?” he says. “That’s what I need to find out.”

He’s given samples to chefs at two restaurants, he’s telling his friends and he’s letting anyone who stops by take a taste for free.

If you take a spoonful of birch syrup expecting some taste cousin to maple syrup, think again.

“I wouldn’t ruin a pancake with it,” New says, with a broad grin as he opens three small jars (from his three boiling runs to date) for sampling.

“When you say syrup, for some reason, people think of maple. It’s not!” New says. “I think it’s fruity, myself. Some people call it tangy. Some call it spicy.”

A taste from the first jar seems overly sharp in my mouth with a strange after-flavor, but the second is better, delicious: sharp and sweet, with a citrusy edge. The third is the sweetest but not as interesting. I think of how this stuff might be really good in salad dressing.

New starts to list recipes he’s heard of for birch syrup: “you’ll find it in sauces and glazes. They use it on salmon, seared scallops, glaze on chickens. You can make a pecan pie out of it,” he says. “I have a friend down the street making birch bars instead of maple bars.”

Crazy weather

Abby van den Berg, an assistant professor in UVM’s Plant Biology department, doesn’t see birch syrup replacing maple. Instead she’d like to know if it can be produced just as the maple season is wrapping up, adding to producers’ bottom line. Maple sap runs when it’s freezing at night and warmer by day. Birch sap, driven by root pressure rather than stem pressure, only starts to run when it stays above freezing in the spring. For a typical year in Vermont, this means late March into April.

2012 isn’t proving to be a typical year, van den Berg says, as she wends her through the tree stand toward three large clear plastic tubes that are being used to collect the birch sap. Nothing seems to be flowing. It’s too cold today. Snow sifts down like sugar, collecting on the tree trunks. But a few weeks ago, it was 86 degrees here at the Proctor Center.

“I have seen a lot of things out here,” van den Berg says, “but nothing like this crazy warm weather this spring.”

And that might be a problem in the short run for van den Berg’s experiment and for New’s syrup making: the early high temperatures not only brought the maple season to an unfortunate early end, but it may do the same to birch, or give the sap unpleasant “buddy” flavors as the trees start their spring metabolism, budding out very early.

“This year may be a dud, but I don’t expect this project to be a dud,” van den Berg says. “I expect the numbers for this will work out.” Part of the reason for her optimism is that birch syrup production could use a great deal of the equipment already in place in an existing maple operation, “your evaporator, your sap tanks, your pumps,” van den Berg says.

“Birch trees are already present in a lot of sugarbushes,” van den Berg says. Ambitious sugarmakers could follow up their six or eight weeks of maple syrup making with two or three weeks of birch. And that would have ecological benefits too. “If birch become a species of value,” she says, “producers are more likely to want to keep them and thus keep more diversity in our forests.”

Maple syrup production seems as established a part of northern New England as, well, maple syrup on pancakes. But it’s under threat. The cost of owning land is rising, as is fuel, and other production costs. Climate change too poses a threat as the sugaring season gets shorter and the long-term viability of maples comes into question.

“We’ve had calls and interest about birch from producers all over the place,” van den Berg says. “They’re very keen to find things that will extend the season, make a little extra money — and just experiment with something new. That’s the culture of maple producers.”

Like undergraduate Teague Henkle who is helping van den Berg on the experiment. “To be honest, I’m not a big fan of how birch syrup tastes,” he says, “but it’s really interesting to be part of adding a whole new business in Vermont.”