Jim Burns uses a hydrometer to measure the sugar content in his maple syrup. (Photos by Lisa Aciukewicz)

Jim's daughter, Gwyneth, holds up a set of bottles that show the colors of each grade of syrup.

Pushing a mini wheelbarrow of wood, Jim’s five-year-old son, Harry, has been helping out since he was two.

In Harvard, and in northern climes throughout the U.S., the flow of maple sap heralds the return of spring. Many people consider it to be the first crop of the agricultural season. Collecting maple sap is a New England tradition that dates back to the first Native Americans, who dubbed the liquid "sweet water."

As you drive north on Ayer Road very early in the spring, you may notice a steady ribbon of steam and an intoxicating aroma emanating from the backyard of a certain antique farmhouse. You will discover that the sweet smell is coming from the sugar shack of Harvard native Jim Burns, situated in a small cove of trees behind his barn, where he boils the maple harvest into what many New Englanders call "amber gold."

On any given week from late February through April, you will find Burns working vigorously to keep the fire burning in his 2 x 6-foot, raised-flue, woodburning evaporator. Burns, a self-taught maple-sugar maker, has been taking his "hobby" seriously for about 13 years. He has attended the Vernon-Verona-Sherrill High School Maple Industry Conference in Verona, N.Y., three times. This nationally and internationally recognized conference hosts more than 800 hobbyists and professional sugar makers from as far away as Sweden every year. Sugar makers flock there to hone their craft by attending workshops and presentations, and to meet with agricultural advisors. Burns has also served on the board of directors for Massachusetts Maple Producers Association (MMPA), a nonprofit organization dedicated to the preservation and promotion of maple sugaring in Massachusetts. Its members are active producers of maple products who support research about factors relative to the industry.

Generally, it takes 40 gallons of sap to yield 1 gallon of syrup. And, for every 25 gallons of syrup generated, it takes one cord of wood in fuel. This process, known as evaporating, is an important factor in syrup quality. According to Burns, the target temperature of the liquid is 7 degrees above the boiling point of water on the day he boils. Since the state of the atmosphere varies daily, so does the time it takes him to reach the standard. Other factors, including cleanliness and type of collection materials used, also affect the quality of the product. In the past, only metal containers were used. However, plastic tubing and buckets have become increasingly popular.

Burns stresses the importance of equipment and timing. "I have had people offer to give me all kinds of things to store the syrup in," he says. "Even though they think they are clean, it is extremely easy to impart unwanted flavors into the syrup. Sterile vessels are best. Basically, all sugar makers have a common goal—they just want to get it done and make the highest quality product with the sap at hand. With that said, there are definitely some things that are just out of your control—like the weather. As the season changes, so does the sap you collect. The weather definitely affects the color of the syrup," he says.

The color of the syrup relates to its grade category. There are four grades of maple syrup:

• Grade A-Light: light-amber in color, with a mild flavor. From the earliest sap of the season; also the most expensive.

• Grade A-Medium: medium amber in color; the most popular grade.

• Grade A Dark: dark amber, with a hearty flavor.

• Grade B-Very Dark: with a robust flavor; used mostly by commercial manufacturers who add other ingredients to create "maple flavored" syrups; also the least expensive.

Constantly in motion, Jim Burns rounds the corner of his boiler to load more wood into the woodstove in his Ayer Road sugarhouse.

On average, Burns makes about 50 gallons of syrup a year. He sells his syrup under the label Harvard Maple Producers for about $60 a gallon. "Some people charge more for the amber syrup," he says. "It takes the same amount of sap and work for all grades, so I charge the same amount for each one." He has no shortage of customers, he says, and sells out every season. Occasionally, if demand allows, he sells through Doe Orchards or at the Harvard Farmers' Market.

Burns collects sap from various locations around Harvard, including the Shaker Village. Since the season is so short, he is constantly working at tapping, gathering, boiling, and packaging, only to start the same routine over the next day.

For Burns, sugaring is a family affair. His wife, Chris, 13-year-old daughter Gwyneth, and 5-year-old son, Harry, are all part of the process.

"I help gather the buckets and I help getting all the bottles ready for selling," says Gwyneth. "I put on the tags and organize them. I don't remember not helping. A lot of my friends think it's fun. They usually ask me for syrup."

Chris calls her husband's hobby "the family rite of spring." "Actually, I don't mind," she says. "He used to race motorcycles. At least this is safe, and something the kids can get involved with."