In New England and parts of Eastern Canada, maple sugaring is both a longstanding tradition and a thriving industry. Although commercial operations use a variety of high-tech equipment to produce large volumes of syrup efficiently, the basic process has remained unchanged since the days before Europeans first arrived on the continent. It consists of "tapping" a tree for its sap, then boiling down the sap to concentrate its natural sugars. Maple trees are best because of the high sugar content of their sap, but birch or black walnut trees can also be used to make syrup.
Select trees for tapping during the fall and winter. Look for trees with trunks that are at least 10 to 12 inches in diameter, 4 feet from the ground where you'll be tapping them. Trees with relatively short trunks and a broad spread of branches produce the most sap.
Tap your trees in the very early spring, when the nights are still freezing but daytime temperatures become warm. Using a cordless drill, make a hole the same size as your spouts, or "spiles" as they're called. This will usually be 5/16 inch or 7/16 inch in diameter. The holes should be approximately 2 inches deep, into healthy wood and 2 to 4 feet from the ground.
Hang your collection bucket on the spile itself, if it's designed to hold a bucket, or by nailing a bucket support to the tree. The buckets can be food-safe metal or plastic, and should have a lid. Some suppliers sell sap-collection bags, which minimize foreign matter in the syrup.
Empty the buckets as they fill, into a food-safe storage container or directly into the pot you'll use to boil down the sap. Syrup is best when made as soon as the sap is harvested.
Line a colander with several layers of cheesecloth, and strain the sap into your boiling pot. Heat the sap to a boil and allow it to reduce, over an outdoor gas burner or a wood or charcoal fire. Top up the pot with fresh sap periodically, as necessary. You'll need an average of roughly 40 gallons of sap to make 1 gallon of syrup, so a lot of steam is produced. It's best to do this outside.
Boil down the sap until its temperature rises above the boiling point of water -- 212 degrees F at sea level and lower at higher elevations. Monitor the syrup's temperature on a good candy thermometer with a large scale, so you can read it accurately. When the temperature reaches 7 degrees above boiling, your syrup is at the correct concentration.
Pour the hot syrup into sterile jars, filtering again through cheesecloth, and seal them well. As long as the syrup is over 190 degrees F when packaged and sealed, it will keep for several months. It can also be frozen for later use.