Through March and most of April, as winter gives way to spring, there occurs in the northeastern United States the mysterious process that brings us maple syrup.

Actually, at $10 or more a quart it very rarely brings syrup to me and mine. But a generous relative from upstate New York sent us a two-quart can for Christmas.

As the last few golden drops sank into the last stack of whole-wheat buttermilk pancakes, we asked ourselves -- rather peevishly -- why such a fine natural sweetner should be so costly.

A little investigating made the reasons perfectly clear.

Before a tree (a sugar or rock maple) is worth tapping, it has to be 40 years old and a foot through.

Each tree produces about eight gallons of sap, and most of the sap is water. Given the 2 percent concentration that's typical, it takes about 40 gallons of sap to produce 1 gallon of syrup. To boil that 40 gallons down requires a log the size of a man (split, sawed and dried), or four gallons of oil. Today, wood and oil are used at about a 50-50 ratio.

Real/maple syrup is far more intriguingly flavored than maple-flavored corn syrup, and it's less caloric, too. A teaspoon contains 40 calories, while corn syrup has 60. (Imitations compensate for the lack of subtle essences like "ethylvanillin" and "furanone" by simply intensifying the sweetness.)

Here are two delicious ways to use maple syrup. MAPLE-PECAN MUFFINS (Makes 12 small muffins) 1 1/2 cups whole-wheat flour 1 1/2 teaspoons baking powder 1/2 teaspoons salt 1/2 cup chopped pecans 1/4 to 1/3 cup maple syrup 2 tablespoons soft butter or oil 1 egg 2/3 cup water 1 teaspoon vanilla

Grease a 12-cup muffin tin. Sift flour, baking powder, salt. Stir in nuts. Beat syrup and butter or oil, and add egg. Add water, vanilla and the dry ingredients, stirring just enough to mix. Spoon into muffin tin, and bake 12 to 15 minutes at 375 degrees. MAPLE RICE CREAM PUDDING (Makes about 4 cups) 1/2 cup uncooked brown rice 1 cup water 1 teaspoon oil 2 1/2 cups milk 1/2 cup raisins 1/4 cup maple syrup 1/4 teaspoon salt 3 tablespoons whole-wheat flour 1 teaspoon vanilla 1/4 cup chopped toasted nuts

Cook rice for 30 minutes in water and oil by bringing to a rolling boil, covering tightly, and turning down to a low simmer.

Add milk and raisins and bring to a boil again. Cover and simmer for another 15 minutes. Stir in maple syrup and salt.

Stir the flour with 1 cup of the rice mixture. Return to pot and simmer 5 minutes more, stirring constantly. If the flour forms lumps, beat with a rotary beater for a minute.

Cool slightly. Stir in vanilla and sprinkle nuts over top. Serve warm or cold.