How to make your own maple syrup

Sap, straight from the tap, is almost entirely water and makes a refreshing drink.Elspeth Hay for The Boston Globe

Before I was born, my parents started tapping a big red maple in our front yard in midcoast Maine. You can tap any kind of maple — not just the sugar maples, though they have the highest sugar content — but also black, silver, and Norway maples and even birches, black walnuts, and box elders.

But by the time my sister and I came around, my parents had given up tapping their own tree and instead boiled down true sugar maple sap from our neighbor Chuck’s trees. It made a butter-flavored, honey-hued syrup unlike anything I’ve ever tasted from the store, and my sister and I devoured it on pancakes, waffles, and snow.

This winter my husband and I decided it was time to learn alongside our own kids how to tap a few sugar maples and make syrup of our own. With the help of a few neighbors and plenty of reading, here’s what we’ve learned.

THE TREES

You don’t need many trees to make backyard syrup — neighbors and books told us to expect enough sap over the course of the season to make about a quart of syrup per tap. Sugar maple sap is roughly 2 percent sugar, so you need 40 quarts of sap to make a single quart of syrup. We tapped two trees and made a little less than a half-gallon.

The trick is identifying which trees to tap. This time of year subtleties in branches, bark, and buds are the best guides to identifying sugar maples. Look for opposite branching; buds that are slender, pointy, and brown; and gray-brown bark with large ridges and valleys often described as “shaggy.” Finally, look for trees at least 12 inches in diameter — any smaller and you risk harming a tree by taking too much sap.

And if you don’t find sugar maples, that doesn’t necessarily spell defeat. You can tap a long list of other species. Read up on your trees first, as most produce sap with lower sugar content and a variety of flavors, and many start their sap “runs” at slightly different times of year.

WEATHER

Sugar maple sap “runs” start when daytime temperatures hit the high 30s and low 40s.

“The big question is always how long is the season going to last,” my parents’ neighbor Brad Babson of Brunswick, Maine, says. “It’s all driven by temperature — it has to be below freezing at night and above 32 during the day, and if it’s rainy or windy, flow is not as strong.” Sap flow also varies by tree — some start giving sap earlier in the season than others.

There are often several “runs,” or warm spells, in each year’s sugaring season, followed by lulls where temperatures drop again and sap slows or stops flowing. Sugar season ends when tree buds swell and break.

EQUIPMENT

Most New England hardware stores sell sugaring equipment. For each tap you need a spile, a bucket, and a lid, all of which come in either metal or plastic. Some more serious setups also connect trees to a central collection vat using gravity and plastic tubing — the most ingenious one I’ve seen was filling a retired bathtub.

Craigslist is a great spot to look for used gear — we found a set of 15 used metal spiles, buckets, lids, and an evaporating pan locally for $150. Prices for new gear at local hardware stores seem to run between $20 and $30 for each complete tap setup, so it can be worth a little hunting around.

To set the taps you also need a power drill, a hammer, and a 7/16-inch drill bit (a 3/8-inch bit will do in a pinch). A neighbor reminded us to set the taps low if snow drifts are deep — otherwise it can be impossible to reach your buckets once the snow melts! — and drill in with the bit angled slightly up to a depth of about 1.5-2 inches. We used a hammer to drive the spiles (with hooks) into the trees, hung the buckets, attached the lids, and listened for the rewarding ping of sap drips.

SAP TO SYRUP

How fast the sap flows is highly variable, but you want to collect the sap every few days whether buckets are full or not, otherwise it can spoil. Brad Babson says he boils twice a week, even if it’s a small batch.

Wide, shallow pans are best — our friends Nat and Genie Wheelwright in Harpswell, Maine, invested in an evaporation pan about a meter square. “We just build a little wood fireplace outside with cinderblocks and rest it on top,” Genie says. “Then we put a screen over the pan so the ash doesn’t end up in the syrup.”

Boiling outside is key — our neighbor Chuck was banned from boiling sap inside after the wallpaper started to slide down the walls in the kitchen one sugar season. Most people recommend doing the initial boil outside; once you’ve evaporated most of the liquid, you can finish inside on the more controlled heat of a kitchen stove.

Sap is officially syrup when the boiling temperature reaches 219 degrees; any less and you risk mold forming during storage, and any more and you risk crystalizing the sugars and scorching a batch. If you don’t plan to use the syrup within a few weeks, it should be canned and strained through cloth or felt to avoid “sugar sand” (concentrated minerals, also called “niter”) settling in the bottom of the jars.

The first run of each season usually produces the lightest syrup, and with each consecutive run the sap picks up more minerals from the tree’s wood and the syrup gets darker and darker.

A CELEBRATION OF SPRING

We realized after our first batch — and a celebratory pancake breakfast — that you can’t buy syrup as tasty as what you make yourself. This is partly because of the flavor, but it’s also about the process — it feels good to be outside with purpose after a winter cooped up.

“I have enough chairs so we can sit around and have coffee on a boil day and cook hot dogs in the maple steam and have a nice chat,” says Brad Babson. “It’s a very social time.”

The season culminates this weekend with Maine Maple Sunday — a celebration of maple syrup and spring at nearly 100 sugarhouses across the state. Learn more at mainemapleproducers.com.