CONCORD, N.H. — Birch syrup? Beech? Walnut? Sycamore? Maple trees — and the sap that flows through them — reign supreme for syrup-making in New England. But with a record-warm winter, some maple syrup producers have seen a decline in their production this year. The season got underway earlier than usual in the southern part of the state, and there were several stretches where the temperature did not go below freezing, which maples need in order for their sap to flow. So David Moore, Advertisement Moore believes tapping other types of “A bad maple year may not be a bad birch year,” he said. “From a farmer’s perspective, it’s kind of like diversifying your portfolio.” And there’s an economic incentive: Birch syrup, for example, can sell for While scientists have a good understanding of sap flow in maples, Moore said little is known what causes it to flow in other types of trees. To create maple syrup, producers first need to harvest a lot of sap. Producers will often concentrate the sap through a process called reverse osmosis, which uses high pressure to reduce the sap’s water content. Then it’s boiled for several hours to evaporate more water, until the sugar content reaches the right level. As he looks for maple alternatives, Moore weighs different factors like how much sap a tree produces and the sugar concentration in the sap. Plus, he has to consider taste, and whether Advertisement Steven Roberge, a forest specialist with the University of New Hampshire and a maple expert, called Moore’s work foundational. “He’s really looking at, like, which trees can you tap? Which trees can you extract syrup from? How do you boil that syrup?” Roberge said. “Because that’s all really unknown.” While a few producers have been able to make alternative syrups, Roberge said, there’s been little research about sap flow, work he believes can help farmers decide whether to adapt new practices. Before Moore started studying alternative syrups, he was farming them : he spent more than five years making and selling birch syrup on a farm in Durham. One year, he also made sycamore syrup. He said people’s reactions varied wildly from those who were exclusively committed to maple, to those eager and excited about something different. “One of our goals is to develop all these new flavors that consumers can be excited about,” Moore said. Advertisement That can benefit the environment by providing an economic incentive to protect forests. Michael Farrell, who led Cornell University’s maple syrup research station for 13 years, is one maple farmer who saw an appealing business prospect in alternative syrups. In 2016, he founded New Leaf Tree Syrups, which he said is currently the only commercial producer of beech syrup in North America. The operation also produces maple syrup, in addition to birch and walnut. “It was a great way to fully utilize the forest,” Farrell said, about working with four types of trees instead of just one. He said he can use the same land and equipment he uses for maple to tap birch and beech. “It provides the incentive to keep a healthy, diverse forest,” he said. When it comes to flavor, Farrell said birch syrup is the most distinct from maple: it’s more fruity, like molasses, and it’s more often used for cooking or to create a dressing or marinade. Beech and walnut have a similar sugar profile to maple, said Farrell, noting that beech is carmelly, with notes of raisin or fig. Walnut, he said, is more nutty, with a butterscotch or honey flavor. Farrell said while people look to maple syrup as a part of their typical grocery list, alternative syrups with a higher price tag are a more niche market, reserved for special gifts or a serious curiosity. Still, he said there’s been consistent demand for his products. In northern Vermont and New York, Farrell said he’s had a good year for maple and alternative syrups. And he believes tapping diverse trees sets his operation up to be resilient in the face of climate change and other challenges. By tapping more trees, there’s less risk to producers if one species gets hit by pathogens or pests. Advertisement Meanwhile, farmers with smaller maple operations that are farther south have noted that their production is down this year. Marc Fortin who runs 2 Sappy Guys in Bedford said he made half the syrup this year compared to last year. He said he started tapping about a week early, and production slowed after things warmed up. And Mike Ackerman who runs Ackerman Brothers Maple, a small hobby farm on his parents’ property Merrimack, estimated he’s at about 60 percent of what he normally produces. “We’re supposed to have a few feet of snow in the woods, not no snow in the woods for a month now,” he said. Maple trees need a freeze-thaw cycle for sap to flow, but if it doesn’t stay cold enough, that can’t happen. Ackerman said he’s heard of alternative syrups from trade magazines and he’d consider doing it, except the property he farms mostly has maples. Roberge, the forest resources specialist, noted that the warm weather brought on by El Nino and climate change pushed the season early in the southern part of the start, with sap starting to flow as early as December. He said climate change may shorten and shift when sugaring season occurs, but as long as there’s a winter, he believes the tradition will go on. Advertisement “I don’t think we will ever replace maple syrup,” he said. Amanda Gokee can be reached at amanda.gokee@globe.com. Follow her @amanda_gokee.