But inside the sugarhouse there is also grave concern. The harvest, in a word, has been abysmal. Not in decades has the weather been so truculent or Lewis' worries so great.
"This is a bad year; it really is," lamented Lewis, a solid, friendly man with a thick face and the large, hardened hands of a dairy farmer, his other occupation. "I said if it didn't straighten out by this weekend, I'm going to pull it down (stop sugaring). I've got lots of other work to do."
Lewis' sentiments match the feelings of maple producers across New England, who last month welcomed the first run of sap with much more nervousness than optimism.
Already hurting from several years of poor crops, they were remembering last year's devastating defoliation by a minuscule insect called the pear thrip. During the wet, cool spring, the thrip bore into the developing buds of the region's sugar maples.
Hardest hit was Vermont, where one in every three trees is a maple. Nearly half a million acres in its southern counties - one-sixth of its forests - were stripped. By mid-June, usually verdant hills and mountains lay colorless and bare.
"I could stand over by the barn door and day after day watch it come around," recalled Lewis, whose farm is only two miles from the New York border in Bennington County.
No one knew what the thrip attack would mean for this year's maple syrup. In a normal year, the crop is worth $17 million, and Vermont's 3,000 sugar makers produce almost $13 million of that, about 370,000 gallons.
People feared that the insects had further stressed their beloved trees, already believed to be suffering from acid rain, drought and general decline. So some sugar makers decided not to tap at all in 1989. Many others, Lewis included, cut back significantly. Unfortunately, they still do not know whether any of that mattered. The spring weather has been so difficult that it has obscured all else.
"This could be the worst year in about 30 years," said Wilson Clark of Wells last week as he labored over troughs of thick, roiling syrup in his sugarhouse, about 10 miles up the road from Ed Lewis.
Clark is president of the Vermont Maple Sugar Makers Association. He has been sugaring since he was 12, meaning he has been at it a decade longer than Lewis. He thought he had seen it all.
Now he's not so sure. "I've got some trees that just aren't running, and if they aren't running by now, I don't see them running," he said.
Even some trees that escaped the thrips aren't running; after two weeks, they haven't produced an inch of sap. Clark said he would be lucky to boil 500 gallons. That's a little more than half his usual syrup crop, or "surp" as he and other people in these parts pronounce it.
"I've never seen nothing that incredible," he admitted.
Maple producers enjoy even less control over their destiny than other farmers. In the space of just six weeks, they must have perfect weather conditions: freezing nights and above-freezing days. Without them, the sap simply won't rise.
Yet early last month, around town-meeting time, when temperatures should have been rising, New England sugar makers suffered through bitter cold, with sub-zero temperatures. And, for the last several weeks, many have been frustrated by nights that have stayed well above 32 degrees.
The combination has crippled the industry in both Massachusetts and New Hampshire, which may record only half their usual harvests.
Only in northern Vermont, where the season arrives later, do conditions remain somewhat favorable. And since that area is the state's largest producer, it could do much to salvage the season. Retail prices are expected to hold between $35 and $40 a gallon.
In northern Vermont, though, trouble may loom for future years. Recent soil surveys show that the thrips have traveled to the northern and central regions and are more numerous there now than they were in the counties defoliated so badly last year. Researchers are unsure of their impact but are warning of greater potential damage.
"You can't do anything about it," Marie Lewis said matter-of-factly last week as she helped her husband in the sugarhouse. Not since four days before had there even been enough sap to boil.
Steam swirled upward behind her from the 14-foot-long evaporator pan in which thousands of gallons were being reduced into hundreds of gallons of amber-colored syrup. The air was redolent with the cloying smell. It was like breathing sugar.
Outside, on the dreary, rain-soaked hills, several of the Lewis children were gathering whatever last sap might have flowed the day before from their father's 5,000 taps. Only half of those taps were marked by the familiar roof- covered buckets seen in sepia-tinged photographs. The other 2,500 are connected by rubber capillaries, a vast hillside network of thin, colored tubing.
"This makes three bad years," said Lewis, who acknowledged, sadly, that despite himself he has considered giving up sugaring. It accounts for one- fifth of his income.
"If I have another bad year, I'm afraid so. There's no use tapping out and killing the trees and only making a little money at it."