Mild weather has settled in across much of the state this week for the first time since December. For sugar makers, the blast of warm spring air is raising concern.
Robert Haynes, a meteorologist with the National Weather Service in Burlington, said the warm weather will persist through late this week, when temperatures are expected to drop again.
“Temperatures [this week] are anywhere between about 20 to 25 degrees above normal for this point of the year,” he said, part of a warming trend for springtime in Vermont.
"It's so delightfully warm and sunny and warm at night that I think it's great to be alive, but it's a wretched time to be making syrup.”Willis Wood, Weathersfield sugar maker
Willis Wood runs a 4,000-tap sugaring operation at his Weathersfield farm. He boiled sap this week and said the trees have been running.
“We've barely just begun,” he said. “Now it's so delightfully warm and sunny and warm at night that I think it's great to be alive, but it's a wretched time to be making syrup.”
Sap runs when it is above freezing during the day and below freezing at night.
Wood's concerns are twofold: that warm temperatures this early will cause the maple trees to bud out and put their energy towards leaf out instead of making sap, and that the warm weather will make this year’s syrup darker and lower volume.
Wood's concern about the flavor of his syrup is one Tim Rademacher, a plant biologist who leads the University of Vermont’s Proctor Maple Research Center, said is spot-on.
“Sap is basically sugar water, right?” he said. “And sugar water is a really attractive growth medium for bacteria and microbes. So if it gets warm enough, there's nothing constraining growth of bacteria and microbes in the tubing.”
This can lead to darker syrup and less of it.
Rademacher is working on research now that he said shows people are sugaring much earlier than they used to, and that climate change is a major factor driving that change.
Vermont is warming faster than the globe on average, and the state is seeing overnight lows warm particularly quickly, especially during the spring and fall. Lakes and ponds are icing out earlier by the decade.
“The way things are going in terms of warming trends and so on, we will still be sugaring [in Vermont] for one or two generations. But you know, when it comes to your grandkids, like that's where the biggest impacts will be seen and that's where, at the moment, we are still in charge of our own destiny to a certain degree, and it depends on the decisions we take nowadays,” Rademacher said.
Willis Wood, the sugarmaker, said — at least according to family lore — his ancestors boiled sap as late as April back in the mid-1800s.
And while modern equipment makes it easier to collect sap earlier, he said, “That earlier syrup is because, in my opinion, of climate change and the weather. You know, spring coming earlier and winter being shorter than historically has been the case.”
Wood forecasts a short season with dark syrup if things stay warm. And if that happens, he’ll be hoping for a good apple year.
Rademacher said looking at the forecast, he doesn’t expect this warm spell to be persistent enough to cause maple trees to bud out.
“If it stays warm, then it could be really a disastrous season,” he said. “But if it cools back down, and we keep getting good temperatures around the freeze point, it might actually turn out to be a pretty good season.”
