WESTVILLE — Anyone walking into the small shed deep within Forest Glen Preserve would immediately expect to smell smoke, as white, translucent clouds roll off the metal table.

Instead, a sweet aroma greets visitors — the sweet smell of pancakes.

It’s the atmosphere Jerry Leahy works in for about a month each year as one of four Forest Glen employees who handle the daily task of creating the park’s maple syrup.

“There’s nothing that smells like it,” said Leahy, standing over a shallow pan filled with rolling, bubbling tree sap.

Set up in a shed dubbed the Sugar Bush, Leahy and others work throughout February and March turning sap from hundreds of sugar maple trees to the dark-colored syrup people enjoy on pancakes and waffles. Buckets hanging from taps in sugar maple trees throughout the park collect the sap.

The process is more than just another job for the Forest Glen personnel, who have turned the process into an educational opportunity for local schoolchildren. Buses bring kids ranging from first through eighth grade out to the site, where they observe the work from beginning to end and get to taste the final product.

Young or old, the process is a little confounding for first-timers who are used to getting their syrup in plastic bottles at the grocery store.

“People who have never seen it go ‘What are those buckets on those trees?’” Leahy said, laughing. “I say, ‘We’re milking the trees.’ I mean, they have no idea what that’s about.”

Park tradition

A process that dates back to the early Native Americans has become a long-standing tradition for Forest Glen Preserve personnel, so much so that the park is the third biggest producer of natural maple syrup in central Illinois. Funk’s Grove in Shirley, southwest of Bloomington-Normal, is the top producer.

Leahy said park environmental educator Gary Wilford first had the idea of trying to make natural maple syrup.

“He knew we had enough trees, so we just started to do it on a small basis,” Leahy said. “We decided if we have enough trees, let’s do it.”

A 10-foot long evaporator is at the center of the process for Forest Glen. Situated in the center of the Sugar Bush, the device consists of two large rectangular stainless steel areas: a starting pan and a finishing pan. Clear sugar maple sap — also called sugar water — is poured into the starting pan where it is heated to more than 200 degrees.

As it is heated, moisture begins to evaporate from the sap, concentrating the sugar content and eventually leaving the caramel-colored finished product. As more moisture evaporates, the fluid moves through sectioned areas of first the starting pan and then the finishing pan, both of which are slightly tilted to move the most dense fluid to the end where a tap is used to drain it from the pan.

“As it boils, it gets more color in it,” Leahy said. “At the start of the season it’s lighter but by the end of the season it’s the darker syrup, full of body.”

It’s a process Leahy has been doing almost since the beginning of Forest Glen’s syrup-making days in the mid 1980s. Gauges on the evaporator show the temperature of the sap, but Leahy — given his experience — simply eyeballs the procedure as it goes.

“I just watch the sap myself,” he said. “Some people watch the temperature.”

Leahy keeps the large pans hot by feeding in wood from a nearby pile in the Sugar Bush. As fluid levels drop, gravity feeds more into the starting pan from a nearby tank in the rafters of the shed. A 200-gallon tank sitting outside the building stores extra sap until its time to cook.

A hydrometer is used to measure the density of the fluid before it’s drained out. Once it is drained, the maple syrup goes through two filters before it is taken to the park kitchen where it’s bottled to be sold.

Years of tradition, however, haven’t made the process any more efficient. On average, Leahy said it takes between 40-50 gallons of sugar maple sap to make one gallon of syrup.

On nature’s terms

There are several factors that decide how much syrup Forest Glen can make in any given year. And unfortunately, few of those variables are under the control of park personnel like Leahy.

“Weather plays a big part,” Leahy said. “We need 20s at night and 40s during the day.”

The varying temperatures make the sap flow more freely from the trees. Constant temperatures, however, slow down the sap and hurt production — even with as many as 400 trees tapped at one time.

Trees are tapped in the middle of February and workers start collecting that week because the season will only last until the middle of March.

“We’ve made as little as 30 gallons and as much as 120 gallons,” Leahy said. “It varies and it’s changed since we first started.”

That combined with the labor-intensive process has led to less and less people willing to do it anymore, Leahy said. But Forest Glen has continued and taken pride in the process.

“We have people from Vermont that say this is even better than what they’ve got,” he said. “It’s a fuller body.”