Squeezing syrup from sap with high-tech help

The murmur of distant snowmobiles and a cold slap of wind are icy reminders that mid-March is practically still the dead of winter here in the North Country. But a sweet whiff of brewing maple syrup, borne down the mountain valley on a white plume of steam, carries with it a hint of spring.

That hint means the sap is running in the Green Mountains of Vermont, and maple sugaring, a tradition that predates the first white settlers in the region , is under way for another year. The timeless process of tapping maple trees, gathering sap in buckets, and boiling it down to create a rich syrup conjures up nostalgic feelings for the simple pleasures of country living.

Well, maybe not so simple any more.

Inside William Coombs's sugarhouse on Beaver Brook, a mysterious new machine with an appearance matching that of a mainframe computer stands in conspicuous modernity next to a flaking and rusty sap holding tank. The sleek new intruder is replete with gauges labeled ''concentrate bypass'' and ''system leakage alarm.'' It was bound to happen.

High-tech has reached the sugarhouse.

The age-old process of turning maple sap into syrup and other maple products has been transformed.

The sap of the maple tree usually contains only 2 or 3 percent sugar. The rest is water. Until a generation ago, maple sap was placed in a large kettle over a wood fire and the excess water boiled off to create syrup. Then oil-fired boilers were introduced, but the process remained basically unchanged from that used by Vermonters - and Indians before them - for hundreds of years. But no longer.

A new stage called reverse osmosis has been added to the boiling procedure, and the machine that accomplishes the task is known by its trade name, Memtek.

Instead of boiling off the water, the Memtek system forces large amounts of sap against a filter membrane at high pressure. Since sugar molecules are larger than water molecules, the latter pass through the filter and are siphoned off. What's left is a maple concentrate that needs a minimum of additional boiling.

''Sure it's a break with tradition,'' says William Coombs. ''But tradition would break me if I didn't modernize.''

He installed a Memtek last year and used 80 percent less fuel than the previous year, when he was depending solely on an oil-fired boiler. ''I've stayed in business because of the machines,'' he says.

Mr. Coombs is a dealer for the manufacturer of Memtek. He has sold a number of the machines in Vermont, as well as New York, Massachusetts, and Pennsylvania. (About 80 percent of all maple sugaring in the US was done in the Northeast last year). He guesses there are upward of 50 Memtek systems in use in the US, and he estimates that in 10 years, 50 to 60 percent of all sugaring operations in the country will have such advanced technology, up from the 1 to 2 percent that have sophisticated processing equipment now.

The reverse-osmosis process was tried in the 1960s, but the cost of fuel-oil boilers was not high enough at the time to justify production of the Memtek machine. The device didn't start to catch on until 1981. At anywhere from $8,000 to $40,000 per machine, it was not designed for backyard operations, but for those producing thousands of gallons of syrup a season.

Coombs is hoping the Memtek machine and several other advances in equipment design, including a system of interconnected hoses that replaces the bucket method of gathering sap, will help the maple sugar industry as a whole - and Vermont's in particular. The industry has been socked by the twin blows of lower-priced imports from Canada and out-of-state imitation products labeled ''genuine Vermont maple syrup'' which contain less than 3 percent of ''the real thing.''

But does reverse osmosis affect the taste? Professional taste testers in Canada were unable to tell the difference between traditionally boiled syrup and the Memtek variety. And visitors to the Coombs sugarhouse, busy devouring ''sugar on snow,'' a taffy-like concoction of warmed syrup poured over snow, confirmed it was the ''gen-u-ine article.''