Four small glasses of maple syrup from pale golden to very dark beside a bottle of Vermont maple syrup, a stack of pancakes and a maple sugar mold

Maple Syrup: The Complete Guide

Published 9 Sep 20267 min read

Filed under Maple Syrups Bushwick Kitchen Runamok Vermont

Maple syrup starts as sap, collected from maple trees during the weeks when freezing nights alternate with thawing days, then boiled down until about forty-three gallons of typical sap become a single gallon of syrup. The sap carries only about two percent sugar, so nearly everything collected is water that has to be driven off. Syrup made early in a season and syrup made late differ in color and in the strength of their maple flavor, and that difference is what the grade on the label describes. Wood-firing, barrel-aging and infusions push the range further.

How maple syrup is made

Sap runs when nights drop into the twenties and days climb into the forties. As the wood freezes, it draws sap inward from neighboring parts of the tree, a process called cryosuction; when it thaws, pressure builds inside the tree and pushes sap out of any tap hole. A spout and bucket, or a network of tubing, collects it.

Sugarmakers estimate yield with the Jones Rule of 86: divide 86 by the sap's sugar percentage to get the gallons of sap needed for one gallon of syrup. Larger producers run sap through reverse osmosis to remove much of the water before boiling, which saves time and fuel. The concentrate is then boiled down in an evaporator, and the longer sap boils, the darker the syrup becomes.

Syrup is finished at about sixty-six to sixty-seven percent sugar by weight, which it reaches at roughly seven to seven and a half degrees Fahrenheit above the boiling point of water. At sea level that is about 219°F. At 5,000 feet, where water boils at about 203°F, the same syrup finishes near 210°F, so the thermometer has to be read against the local boiling point of water. A syrup hydrometer measures the finished density directly.

What the grades mean

In 2015 and 2016 the United States and Canada moved to a shared grading system that replaced a patchwork of older labels. Retail syrup is now sold as Grade A, followed by a color and flavor descriptor:

Golden, Delicate Taste. The lightest class, with a mild maple taste.
Amber, Rich Taste. A full-bodied maple taste of medium intensity.
Dark, Robust Taste. A stronger maple taste than the lighter colors.
Very Dark, Strong Taste. A maple taste stronger than robust, the strongest of the four.

The four color classes are set by how much light passes through the syrup. All four are one hundred percent maple, and all four sit within Grade A, so darker syrup is not a lower grade. It tends to come later in the season and carries a stronger maple flavor.

Why a season changes flavor

Sap leaves the tree carrying sucrose. Once it is outside the tree, naturally occurring bacteria and yeast break some of that sucrose into glucose and fructose, known as invert sugars, and the warmer the air and sap, the more active those microbes become. Early in the season, cold weather and clean sap handling keep that conversion low, which is part of why the first syrup tends to be golden. As temperatures build, the sap's sugar content falls, microbial activity rises and the syrup darkens: the more glucose and fructose in the boiling sap, and the longer it boils, the darker the result. The pattern is not absolute, and light syrup can reappear at the very end of a season. Sap collected as the trees come out of dormancy gives syrup a disagreeable flavor called buddy, which the federal standards class as damage.

Runamok, a sugarmaker in Fairfax, in northwestern Vermont, samples each run, and when the flavor is at its peak its sugarmakers set that batch aside for Sugarmaker's Cut (shop Sugarmaker's Cut), a USDA certified organic Grade A Amber. Runamok describes it as caramelized maple with depth and nuance.

Wood-fired, barrel-aged and infused

Runamok's Sugarmaker's Dark (shop Sugarmaker's Dark) is a wood-fired, late-season Grade A Dark, and the producer credits the wood fire's slow boil with bringing out more caramelization. Runamok suggests it when a stronger maple flavor is wanted: in cocktails, as a glaze, over pancakes or as a baking sweetener.

Runamok's WhistlePig Rye Whiskey Barrel-Aged Maple Syrup (shop WhistlePig Barrel-Aged Maple) is aged in freshly emptied rye barrels from WhistlePig, the distillery in Shoreham, Vermont, and Runamok tests each barrel until the flavor is where it wants it. In Runamok's tasting note, brown spice from the rye leads, maple's caramel supplies the sweetness, and mild oak comes through on the finish. Runamok suggests it in an Old Fashioned, over ice cream or as a glaze for roasted vegetables.

Runamok's Sparkle Syrup (shop Sparkle Syrup) is pure maple syrup with a flavorless, food-safe pearlescent shimmer, made for pancakes and French toast or a spoonful in a cocktail.

Bushwick Kitchen works the savory end. Its Trees Knees Spicy Maple (shop Trees Knees Spicy Maple) combines organic Grade A maple syrup from the Catskill Mountains with habanero peppers, and the producer suggests it on roasted vegetables, crispy bacon and skillet cornbread.

The numbers, worked out

Two calculations sit behind every bottle: how much sap it took, and when the boil was done. The first table runs the Rule of 86 for sap from 1.5 to 3 percent sugar.

Sap sugar	Gallons of sap per gallon of syrup (86 ÷ sugar %)
1.5%	about 57
2%	43
2.5%	about 34
3%	about 29

Adding seven to seven and a half degrees to the local boiling point of water gives about 219°F at sea level and about 210°F at 5,000 feet, a nine-degree gap that matters to anyone boiling sap in Colorado. The second table maps each grade to where it does its best work.

Grade A class	Light transmittance	Official taste	Where it goes
Golden	over 75%	Delicate: mild	Whipped cream, vinaigrettes, the table
Amber	50 to 74.9%	Rich: full-bodied, medium intensity	Pancakes, coffee, dressings
Dark	25 to 49.9%	Robust: stronger than the lighter colors	Glazes, baking, cocktails
Very Dark	under 25%	Strong: stronger than robust	Baking, glazes, barbecue sauce

How to store maple syrup

Once opened, maple syrup belongs in the refrigerator; an opened bottle kept in the pantry risks growing mold. If mold does appear, the University of Maine Cooperative Extension recommends discarding the syrup. For long storage the freezer works well, and frozen syrup keeps indefinitely without any change in flavor or texture. Crystals at the bottom of a jar come from syrup boiled past standard density, while syrup boiled short of it is the kind that can spoil and mold.

Cooking with the grades

Golden and Amber suit anything where the maple should stay in the background: whipped cream, a vinaigrette, a glaze on salmon, the sweetener in a cup of drinking chocolate (the drinking chocolate guide explains how it differs from hot chocolate). Dark and Very Dark belong in the oven and the shaker: pecan pie, baked beans, roasted root vegetables, barbecue sauce, an Old Fashioned.

A few flakes of finishing salt on maple-drizzled oatmeal, roasted squash or a scoop of ice cream sharpen the sweetness. The finishing salt guide covers which flakes to use. Maple also pairs with dark chocolate, bacon, mustard, vinegar and chile, each of which gives its caramel notes something to push against.

Where to start

Sugarmaker's Cut is the table syrup, and Sugarmaker's Dark goes into glazes and baking. The WhistlePig barrel-aged syrup belongs in an Old Fashioned. Sparkle Syrup is for French toast that wants some shimmer, Trees Knees Spicy Maple for heat. Browse the maple syrup collection (shop maple syrup). Honey gets the same treatment in the complete honey guide. Products ship across the continental U.S. from theambrosianpantry.com. The shop is at 263 Josephine Street in Cherry Creek, Denver.