Not So Sweet: Warmer Temps Disrupt PA Maple Syrup Industry

Featured image source: MTSOfan 

In a typical year, maple syrup farmer Kyle Dewees would be busy collecting sap for his family-run business, Whiskey Hollow Maple. But this is not a typical year.

Warmer-than-average temperatures have impeded what should be the peak harvesting period, reflecting a worrying trend for sugar maple farmers.

Pennsylvania is one of the biggest producers of maple syrup. Last year, 178,000 gallons of maple syrup was made in the Commonwealth, according to the USDA, ranking sixth in the nation. In recent years, annual value of the state’s maple syrup industry has ranged from $5.4 to about $6.1 million.

Effects of Warmer Weather on Syrup Production

February marks the time when farmers begin collecting sap that will turn into that year’s syrup. They install taps in such a way that removes a small portion, usually 10%, of a tree’s sap and doesn’t cause permanent damage. Fluctuations in temperature — ideally above 40 degrees during the day and around 20 degrees at night — are necessary to draw out sap. Human-caused climate change is fueling warmer temperatures in the Commonwealth that, by the end of the century,  are projected to increase on average by 5.27 to 9.11˚F.

In years past, Dewees has continued collecting sap until the beginning of April. But because of an unseasonably mild winter, he stopped by mid-March.

“This is the earliest that we’ve ever been done,” Dewees said.

To help offset, to some degree, the effect of temperature, he’s installed a vacuum pump system that can yield more sap than the conventional gravity method. But, he added, this isn’t feasible for smaller producers, as it costs more and requires constant maintenance to check for and repair leaks (often caused by nibbling squirrels and chipmunks). And in the end, even more sophisticated methods will not guarantee a good harvest.

“We’re mostly just stuck with whatever mother nature gives us,” Dewees said.

Warmer temperatures also create challenges with keeping storing sap. Scott Weikert, a forest resources educator with Penn State Extension, said that farmers rely on colder temperatures to keep their sap from spoiling before they can boil it. When temperatures rise into the 50s and above, it encourages the growth of yeast and bacteria. Warmer weather also causes tap holes to close sooner, which often means smaller yields.

In response, he’s seeing more farmers begin tapping their trees earlier.

“Forty years ago, you rarely had a good run in the second week of January. The last few years it’s not that uncommon,” Weikert said.

Winter throughout much of the Northeast and Midwest was mild and with below-average snowfall. Those conditions lead to earlier spring conditions.

“It was a strange winter,” Weikert said. “We had some really good runs, and then it got so warm.”

One effect of earlier spring is that deciduous trees bud sooner. In the case of maples, the process imparts unwanted flavors into the sap.

“Once the buds break open, it’s done,” Weikert said.

Early flowering can also stunt tree growth and put them out of sync with pollinators.

Finding Solutions

A multi-site study of sugar maples ranging from Virginia to Quebec showed that changes in climate are causing fewer trees to grow, with some areas in the southern half of sugar maple’s range becoming unsuitable for syrup production. They’re not alone. Pennsylvania’s state tree, the Eastern Hemlock, is increasingly vulnerable to the invasive hemlock woolly adelgid, a forest pest that’s proliferated because of warmer temperatures.

In response, researchers have been looking at ways to help trees adapt to the changing climate. One promising tactic has been assisted migration. For decades the U.S. Forest Service has been pursuing the Desired Regeneration through Assisted Migration (DREAM) Project, which works with land managers to identify which tree species may thrive in other areas under future climate conditions.

“In essence, the clock is ticking and trees are struggling to keep pace,” the USFS explains. “As the climate continues to exert pressure on natural systems of plant adaptation and natural migration, DREAM stands to serve as a valuable tool for land managers seeking to ensure forest health and resilience in an uncertain future.”

In his 2024-25 state budget, Gov. Josh Shapiro allocated $2.18 million to fund agricultural research to help address the effect of challenges, including climate change.

Some syrup producers are looking beyond sugar maples. Sugar maples may be the poster tree for syrup, but red maples offer a supply of (quite literally) untapped potential. They’re also the most climate-tolerant species of the maple family. Other trees, like birches and walnuts, also can be tapped for sap.

“The resource is there. Hopefully we can expand that,” Weikert said.

Despite the challenges, Weikert enjoys his humble operation. The first year he made maple syrup, friends and family came to see the process.

“It’s very rewarding,” Weikert said.

Spreading the Syrup

In addition to running Whiskey Hollow Maple, Dewees also serves as President of the Pennsylvania Maple Syrup Producers Council, which represents six regional producers in the state. One of his main goals is raising awareness of the industry and encourage communities to support their local producers.

“For years people walk up all the time and they want to know where in Vermont our syrup is from,” Dewees said. “They have no idea that syrup can be made in Pennsylvania.”

At the annual farm show, he operates two booths: one in the food court to promote products, and the other in the education area to talk to people about the industry.

In recent weeks, sugar houses opened briefly for educational tours along with samples of their products. If you didn’t get a tour, there are still ways to celebrate and support your local syrup farms. VisitPA has crafted a curated road trip called Tapped: A Maple Trail that takes you by maple producers as well as coffee shops, distilleries, candy makers, restaurants, farm tours and historic sites.

The annual Pennsylvania Maple Festival returns to Meyersdale April 20-21 and 24-28. Events include maple syrup demonstrations, a race on the Great Allegheny Passage, a parade, and more. There’s also the Beaver County Maple Syrup & Music Festival, April 20-21, in Beaver Falls, and the Endless Mountains Maple Festival, April 27-28, in Troy.