Maple trees share their sweetness

Late winter is when the sap starts flowing in maple trees, sap that can be boiled down into sweet syrup.

Ideal conditions are sunny days with temperatures in the 40s, following nights when the mercury dips into the 20s.

Even a single tree could yield you over a quart of finished syrup -- a very special treat when you have collected the sap and boiled it down yourself.

Sun warming a tree converts its starches to sugary sap. The tree pumps this sugary sap at about 20 pounds per square inch pressure up into the buds, down towards the roots, and outwards towards the bark. Poke a hollow tap -- called a spile -- into the trunk, and out pours some of that sap. It's that simple.

Buy spiles or make traditional ones from four-inch lengths of half-inch-thick, hollowed out elderberry stems. Stick spiles into tight holes that you drill in the bark, each hole an inch-and-a-half deep and pointed slightly upward. Don't make too many holes, though: none on a tree less than a foot across, one for a tree a foot across, an additional one for each additional six inch diameter of trunk.

No need to find a sugar maple per se in order to make maple syrup. You can also tap sap from boxelder, which is a maple species, as well as red maple, Norway maple, sycamore maple, and silver maple. Each tastes a little different. Not better or worse, just different.

The sap from any of these trees is only about 3 percent sugar, so must be concentrated to make a final syrup of about 63 percent sugar. American Indians made their sisibaskwat ("drawn from wood") by skimming ice off the frozen, collected sap, or by repeatedly dropping hot rocks into wooden troughs of sap. Large batches call for an outdoor kettle and fire, but an indoor stove is fine for smaller batches. Just keep an eye on the sap as it boils because it tends to froth as it nears the final stages.

The easiest way to tell when the syrup is finished is by taste and color. Finished syrup is brown, thick, and very sweet. If you prefer it to be more quantitative, stick a candy thermometer in your boiling sap. Finished syrup will boil at 219 degrees Fahrenheit.

Once you have drizzled maple syrup over flapjacks to your heart's content, what else can you do with it? Vermont Special is a punch made from one part rhubarb juice, one part maple sugar, and two parts rum.