When the nights are below freezing and the days are in the 40s, you'll find Teresa Marrone checking on two maple trees on her south Minneapolis property, watching for the drip-drip-drip of the sap flowing.

"I'm known as the crazy lady in the neighborhood who taps trees in the front yard," Marrone said with a laugh.

Not surprisingly, she has found many uses for this sweet liquid, which she describes in a new book, "Modern Maple," the second in the Northern Plate series by the Minnesota Historical Society Press (168 pages, $16.95). From grilled radicchio with a maple glaze to mulled maple apple cider and maple chicken wings, Marrone offers 75 recipes to please our palates.

A longtime forager, Marrone has written several books on wild foods, including "Cooking With Wild Berries and Fruits of Minnesota, Wisconsin and Michigan," and "Abundantly Wild: Collecting and Cooking Wild Edibles in the Upper Midwest."

The sap for maple syrup comes from a tiny — and very hardy — part of the world, where there is just the right freeze-thaw cycle and where certain types of maples grow. Not surprisingly, that includes Minnesota, the state farthest west for maple syrup production. We produce only small quantities (less than 1 percent of U.S. production). The bulk of the remaining U.S. production comes from the Northeast, with Vermont and New York yielding more than half of the U.S. supply. Most maple syrup (80 percent) comes from a small swath of Canada, particularly in Quebec.

In Minnesota there are only two major commercial syrup producers — Wild Country Maple Products and Caribou Cream, both of Lutsen, Minn. — though smaller processors and hobbyists offer a limited, very local product.

One maple syrup doesn't necessarily taste like another. "We're beginning to understand that syrup has terroir," said Marrone. That's the notion that environment — the soil, the altitude or air, and more — affects the flavor of a food. The term is often used when describing wine or cheese and other foods, including honey. Both Wild Country and Caribou Cream have won national awards for their syrup, beating out the biggies in the field with their flavors.

"What's amazing is that the two syrups [from Up North] taste different from each other," said Marrone. Large commercial producers, such as those in the Northeast, often blend their supplies of maple sap, which results in a uniform flavor that lessens the effect of terroir.

American Indians used maple flavoring — sap, syrup and sugar — as a primary seasoning long before they had access to salt. It still serves a role beyond cooking.

"Maple is more than an important foodstuff to Ojibwe and other indigenous peoples of the area. It remains essential as the first harvest of spring, the life-saving gift of the creator, the blessed substance that once broke the fast of winter's starvation," said Heid Erdrich, a local writer at work on a book of indigenous food stories and recipes.

"Maple sap is also an icon in Ojibwe stories that connects to women and our roles as life-bringers and protectors of the waters of the Earth. This time of year in the Ojibwe calendar is called Iskigamiige-giizis, or Maple Sugar Moon," said Erdrich.

A long process

The buckets, spigots, plastic bags and tubing used in tapping maple trees are just the first step for producing the gooey substance that transforms pancakes into puddles of delight. Once the clear, mildly sweet liquid is retrieved from maples, it's off to the outdoor cooker to boil off the water — and the sooner the better for the best results. (To see the process live, visit a sugarbush; see listing at left).

Instead of a kettle, Marrone fires up a turkey fryer in her yard to cook away the water in the sap. The process, which creates a tremendous amount of steam, transforms what initally is 2 percent sugar in the sap into the 66 percent sugar that syrup has. The final step — "when it's brought down to a respectable volume," Marrone said — takes place on her stovetop, where she cooks off even more water.

For the hobbyist, it's a labor of love. A single gallon of maple syrup comes from 40 gallons of sap.

Color determines the grade of maple syrup. Consumers will find forms of Grade A at the supermarket, from Light Amber (the first sap of the season) to Medium and Dark Amber. Some cooks today reach for the Grade B variety, which is a very dark syrup that results from being tapped further along in the season. Once used exclusively in commercial products, Grade B's strong flavor — twice as much as Grade A — is favored by some bakers and cooks. (Trader Joe's carries it, as do some other stores).

If the only way you've tried maple syrup — and we're talking about the real stuff, not the colored corn syrup that's sold as "imitation" — is on pancakes and French toast, you have some discovering to do. As Marrone found, maple syrup works well as a flavoring agent with a variety of spices and herbs (cumin, sage and thyme, among them) and it has a niche in savory dishes, as well as the more predictable sweet ones.

Cooking tips at home

• Maple syrup is sticky, of course, and that makes measuring a bit messy. If you're using oil in the same recipe as syrup, measure the oil first and use the same utensil to measure the syrup, which will slip out of the oil-coated utensil easier than from a clean object.

• If you have some crystallized syrup at the bottom of the jar, don't toss it. This is more likely to happen with small batches from home producers than a commercially made product. "We don't have the same sophisticated equipment as commercial producers," said Marrone. If you can't dig out the crystals, simply put the container in some very hot water and let it sit a bit until it loosens up.

• Never turn your back on syrup that's on the stove. It can burn or boil over quickly, and is both messy and dangerous, since it sticks to you and is hotter than boiling water. "People don't respect it as much as they should," said Marrone. "When you're cooking with it, you need everything in its place — mise en place — before you start."

• Experiment with some unfamiliar combos with maple as you're cooking. Drizzle maple into your cappuccino or in a malted milk. Infuse bourbon with it or add it to a hot toddy. Roast root vegetables with it or caramelize onions with it. Add it to homemade granola or whip it into butter. "Modern Maple" and Marrone will guide you.

Follow Lee Svitak Dean on Twitter: @StribTaste