Everything You Need to Know About Maple Syrup

How it’s made, graded and how to buy and store it.

Be honest: the last time you thought about maple syrup was when you were scraping out your waffle iron or pancake griddle after that indulgent weekend breakfast.

Which is a shame because maple syrup deserves more consideration. Native Americans were already tapping maples and reducing the sap into syrup in hollowed-out tree trunks when the first European settlers landed and adopted their methods. In the lead-up to the Civil War, northern abolitionists made a point of using maple syrup and maple sugar as sweeteners instead of cane sugar, which relied on slave labor. During World War II rationing, soldiers got dibs on cane sugar, so maple syrup and maple sugar took up the slack, ensuring that Americans and Canadians on the home front didn’t need to take their coffee bitter, or bake bland cakes.

Nowadays, though, most Americans think of maple syrup as cheap, so-called “table syrup” infused with various flavorings like fenugreek, which contains some of the same compounds that give maple syrup its unique taste. (New Yorkers may remember the “mystery smell” of the mid-2000s, which made large swaths of Manhattan smell like an IHOP after Sunday church every couple years. The culprit, it turned out later, was a New Jersey factory that was processing large batches of fenugreek.) Real maple syrup is vastly more complex, and, as both flavor scientists and maple farmers can attest, nearly impossible to describe precisely because it’s such a unique flavor.

“Buttery? Hints of vanilla?” says Amanda Voyer, spokeswoman for the Vermont Maple Sugar Makers Association (or VMSMA), which lays claim to the being one of the oldest agricultural organizations in the U.S. “There’s maybe sixty-three different flavors that can be detected in maple, so it’s hard to pinpoint exactly.”

Today, maple syrup is made in reportable amounts in thirteen states in the U.S., mostly in the Northeast but also in outliers like Michigan and West Virginia, according to the USDA. In 2016, the American sugar makers produced over 4.2 million gallons, with the lion’s share coming from Vermont, which accounted for two million gallons all by itself. Still, that’s dwarfed by the production in Canada, which makes 71 percent of the world supply, and especially in Quebec, which alone accounts for 91 percent of Canadian production. The stuff is so important to Canadian agriculture that the country actually maintains a strategic maple-syrup reserve, which is an easy target for American jokes about their neighbors to the north, but is a large part of why maple syrup doesn’t double or triple in price at your grocery store every time there’s a drought on the East Coast.

How It’s Made

Though the equipment has changed, the methods sugar makers use to make maple syrup today would be instantly recognizable to the Native Americans who first taught the settlers the secrets of the maple tree. Most syrup comes from the sugar maple, though sap from other maple types is often mixed in. The sap can only be collected at the tail end of winter, when it’s cold enough for the sap to freeze inside the tree at night but it’s warm enough for the sap to flow freely during the day.

Farmers bore small holes into the trunks of the trees, into which they stick taps that divert the sap flow out of the tree into a bucket or plastic hose to be collected. Trees typically aren’t tapped until they’re at least ten inches in diameter, and it takes about forty years for a maple to grow to that size. Most farmers put two or three taps into each tree, though the number of taps per tree is creeping upward across the industry as technology improves. The tapping leaves small, round scars on the trees, but doesn’t otherwise harm them.

“We have trees in Vermont that have been tapped for two hundred years, surviving good and strong,” Voyer says. “Think of it as giving blood: you can give a little bit of blood and function perfectly fine.”

The sugaring season varies from year to year depending on the weather and the region, but never lasts for more than a few weeks. Earlier in the season, the sap comes out clearer and sweeter, and is turned into lighter-colored and sweeter but less “maple-y” syrup. As the season progresses, the syrup gets darker, the flavors more complex and maple-y. The season ends once the tree has warmed enough to change its physiology for spring flowering, creating a greenish sap and off smell and flavor called “buddy.” It’s impossible to turn buddy sap into palatable syrup.

“It’s like sweaty socks,” says Ryan Mahar, owner of Mahar Maple Farm in Middletown Springs, Vermont.

Usable maple sap, which is full of the energy the tree has collected the previous year and stored in the form of sucrose sugar, comes out looking nothing like the syrup on your table, but instead like slightly viscous water—clear, colorless, and only slightly sweet, at 2 to 8 percent sugar content. The sap from each grove of maples, or sugar bush, is usually collected daily and then taken to the sugar shack, where it’s heated and the excess water in the sap is evaporated off. It takes about forty gallons of sap to make one gallon of syrup. Back in the day, this involved simply boiling the sap on a wood stove. Today, most commercial sugar makers use much more efficient equipment that has reduced this part of the process from some twenty hours to three to four hours, without affecting the taste.

It’s at this stage that the real magic happens, according to Abby van den Berg, research assistant professor at the Proctor Maple Research Center of the University of Vermont, and one of the industry’s most widely acknowledged experts. Though sugar makers and loyal fans of a specific sugar shack will swear up and down that it’s because of the terroir, or nearby slate or clay deposits, or whether or not the trees were tapped under the shade of a Revolutionary War shack that once housed George Washington, the essential mysteries of the maple-syrup flavor are unlocked during the heating process, thanks to the Maillard reaction, the same reaction makes caramelized onions and seared meat so delicious.

“You have the non-enzymatic browning, the sugar-degradation reactions when sugar meets heat, the Maillard browning,” van den Berg says.

The syrup is reduced until its sugar content makes up between 66 and 67 percent of the syrup by weight. At this point, this reduced tree sap, free of additives, is now officially maple syrup and ready to bottle or consume. Reduced further, it eventually becomes a solid, or maple sugar.

How Maple Syrup Grades Work

Until very recently, maple syrup grades were confusing hodgepodge of federal, state, and provincial standards, with USDA, Canadian, or local labels and even language taking precedence depending on where you were. How did a can of Quebecois “foncé” compare to a jug of Grade B Vermont, for example?

Probably the worst aspect of the old grading systems was that the most familiar ones, at least to Americans, used letter grades to categorize the how light-colored the syrups were, which most consumers misinterpreted as indicators of quality. Thus Grade A (sometimes called Grade AA or Grade A Light Amber, Canadian No. 1 Extra Light or Light, or just Fancy) leapt off the shelves, while the rest, unfairly dismissed as inferior by an uneducated public, were left neglected on the shelves, even if aficionados knew that it was the darker grades that were better for the complex maple notes they prized.

“We’d used to keep the mild grades in the consumer-friendly cans and jugs, and would sell the dark grades for whatever we could get,” says Jacques Couture, co-owner of Couture’s Maple Shop and Bed & Breakfast in Westfield, Vermont, and the former president of the International Maple Syrup Institute.

By the time chefs caught on and started seeking out Grade B syrup in the late 1990s (they were followed by devotees of colon cleanses), the IMSI was already getting the ball rolling on replacing the disparate grading systems with a universal system that was easier for consumers to parse. The new grades, which are now standard among most governmental agencies and commercial sugar makers in the U.S. and Canada, have the additional bonus of expanding the spectrum of syrups available to consumers, including the darkest grades, which could previously only be sold commercially as flavoring agents for other foods. (Quebec adopted the new standards in December 2016 for companies that export syrup outside the province. Sugar makers who sell only in Quebec have until December 2017 to adopt the new grading system.)

The new grading system defines grades both by how much light can pass through the syrup and by their flavor profiles, with the flavors taking precedence in determining what grade is appropriate.

From lightest to darkest, the new grades are:

Golden, Delicate Taste: Golden, Delicate corresponds to the previous Grade A, Light Amber, Fancy, and No. 1 Extra Light grades, has the lightest color (if you shine a light on it, over 74 percent of it will come through) and most overt sweetness.

Amber Color and Rich Taste: Previously Grade A Medium Amber to Dark Amber, No. 1 Light to No. 1 Medium, it’s a somewhat darker color with more complex flavors than Golden, Delicate.

Dark Color and Robust Taste: In the U.S., this was categorized as a darker Grade A Dark Amber or a lighter Grade B. In Canada, this was the darker No. 1 Medium and lighter No. 2 Amber. It’s much darker than Golden, Delicate, or Amber, Rich, and has a strong maple taste.

Very Dark Color and Strong Taste: The darker end of the U.S. Grade B, and equivalent to Canada’s No. 3 Dark (“foncé” or “trés foncé” in Quebec), Very Dark, Strong lets in very little light (25 percent or less will pass through), and has a very strong, sometimes overwhelming maple flavor.

Once again deflating the romantic mysteries of maple syrup, van den Berg points out that maple syrup gets darker and more complex throughout sugaring season not because of changes in the trees or the soil, but mostly because microbes that grow on the taps, tubes, and tanks as the days get warmer convert more and more of the pure sucrose of the sap into glucose and fructose, which break down into compounds with more interesting and complex flavors during the evaporation process.

“You have more of a substrate for Maillard reactions, so more color and flavor develops,” she says.

How to Buy and Store Maple Syrup

Before you go out and buy a gallon of maple syrup, you should know what grade you like best; the differences between Golden, Delicate and Very Dark, Strong are so considerable that you could be forgiven for being surprised they both came from the same tree. Many sugar makers will offer small samples of each of the grades they offer, and you can find your sweet spot, as it were, by trying a little of each, going from lightest to darkest and ensuring that you swirl and swallow, as a lot of more nuanced flavors don’t hit you until they waft off the back of your throat. If you smell mold, or any other questionable flavors, don’t consume or use the syrup. (Smokiness, while it doesn’t make maple syrup inedible or unsafe, is considered an undesirable trait in the industry.)

Keep in mind that, though the general methods of making syrup are the same, every sugar maker’s product will be different from the next, and that you might prefer one place’s Dark, Robust to the one across town; established sugar shacks have loyal customers who’ve been coming back every year for generations. If you get into maple syrup, you’ll probably find yourself gravitating toward the darker syrups as you expand your palate.

“It’s like Mexican food,” says Mahar, who keeps his darkest syrups from each season under a shelf for his own use. “The more you eat it, the spicier you want it.”

Once you know what grade you want, make sure that what you’re considering buying is actually maple syrup. By law, pure maple syrup should be labeled as such, and contain nothing else. Products labeled “maple-flavored” or “natural maple flavor” likely contain the bark of a cousin of the sugar maple, the mountain maple, or possibly maple-syrup concentrate—but it’s not real maple syrup.

To a large extent, the containers the syrup comes in doesn’t matter much, though the experts we talked to preferred glass for avoiding any off flavors, or plastic for convenience. Many said they usually tried to avoid syrup in cans, as is popular in Quebec, as it’s impossible to tell whether a can has been properly lined until it’s too late.

The best place to keep your maple syrup is in the freezer, in the original container it came in, where it can remain indefinitely. The syrup won’t freeze, but will simply become a more sluggish liquid. Once you open a container of syrup, keep it in the fridge, where it will keep for at least a year. Crystallization sometimes occurs in older opened syrup or syrup that’s been boiled beyond 67-percent sugar density. It’s harmless, and can be safely ignored. If it bothers you, you can try gently reheating the container of syrup in hot water, as you would with crystallized honey. It’s normal for maple syrup to darken over time.

In recipes, maple syrup can be used in a 1:1 ratio for honey or corn syrup, and maple sugar can be substituted for an equal amount of cane sugar. If you’re using maple syrup as a substitute for another sweetener, or if you’re making a maple candy, opt for a lighter grade, as the maple notes of the darker grades can be overpowering as it gets concentrated.

Most maple farmers already practice sustainability and best practices with their sugar bushes—their syrup depends on health, long-lived trees, after all—so in most cases organic certification simply means that they haven’t used a chemically based defoaming agent for part of the process. Unless you’re a stickler, you can feel confident that any pure maple syrup is a de facto organic product. “In most cases, there are no real differences,” van den Berg says.