Tapping Spring's Natural Resource

It's impossible to know just when it will arrive, but the smell and feel of a late winter thaw are unmistakable. Regardless of whether it's late February or early March, though, those first bright days of spring are tonic for cabin fever. They also mark the beginning of the maple syrup season.

Scientists are still at a loss to explain the precise mechanisms of maple sap flow, but basically carbon dioxide within the tree expands and contracts in response to changes in temperature. On warm days, increased pressure sends sap coursing to the uppermost branches..

Warm days and below freezing nights over an extended period are the key to a successful season, and the first sap run produces a prized fancy grade of syrup. These days, North Country syrup producers have a keen eye on the weather and very likely their equipment is out of storage, sorted and washed in anticipation of the first sign of the sap run.

Metal buckets and spiles, or metal taps are the traditional means of collecting sap. In recent years, however, many of New Hampshire's large syrup producers have converted to at least partial use of plastic tubing. The initial investment is high, but experts estimate that in the long run, this innovation proves to be 40 percent more cost efficient than buckets. Tubing also takes maximum advantage of the sap flow.

Yet sophisticated equipment is by no means a prerequisite for enjoying the sugaring season, or for producing a high grade of syrup. A variety of paraphernalia can be utilized to collect and boil down sap, and the process can easily be adapted to a small scale. It may not be as efficient as a large sugaring operation, and definitely is labor intensive, but there are few better ways to enjoy the onset of spring.

The first step is to size up your potential maple orchard. The sugar or rock maple is the best choice for syrup, favored for its sap output and the sap's high concentration of sugar. But red or soft maple is acceptable, too, since the species often starts to run earlier than its cousin, even if the sap isn't as sweet. If the property you own or rent doesn't have enough of either to make a go of syrup production, many landowners will be agreeable to having you tap their roadside maples, especially if the bargain is sweetened with a few quarts of the end product.

There are several considerations in selecting the best trees. The optimum maple is a healthy, fast growing tree with a well developed spread of branches, or crown. Trees growing in a thick stand often lack this crown, and on an average produce 30% less sap than an open grown specimen. Also, the larger the tree, the more sap obtained per taphole. A large, roadside maple may yield as much as 50% more syrup than the forest run variety.

Once you've estimated the number of trees available, gather your equipment. Large sugaring operations that have gone over to plastic tubing will often sell their unused buckets and covers at a reasonable rate. The Market Bulletin, available through the N.H. Department of Agriculture, is an excellent source of used equipment.

Other types of containers are perfectly suitable, too, like gallon milk jugs, large coffee cans or even heavy gauge plastic bags. Bear in mind that the minimum capacity should be close to a gallon, since during periods of heavy sap flow, even a regular sap bucket will be full to overflowing by the end of the day.

Another note of importance is that all buckets and taps should be thoroughly cleaned before setting them out. Dirty containers promote the growth of bacteria which can result in a lower grade of syrup.

Tapping the trees will require a hand brace and bit. The bit can vary in size from 3/8 or 7/16 up to 1/2". Choose a spot two or three feet off the ground, preferably on the south side of the tree, and bore a three-inch hole. Avoid deadwood or diseased spots, and drill at least six inches from old tap holes. The depth of the hole will yield substantially more sap than one two inches deep. The spile is then tapped firmly into the hole with a hammer so that the tapered shoulder is flush with the tree to form a tight seal. The general rule for determining the number of buckets to hag is one for a tree 10 inches in diameter (the minimum size), and an additional bucket for each six inches of extra girth.

Once the flow really gets under way, it will be necessary to collect the sap at least once and possibly twice a day. Five-gallon plastic pails, such as those discarded by many restaurants, are ideal for the collecting process, since they are manageable even on a pair of snowshoes and are easy to keep clean. A larger container, such as a plastic garbage can, will be needed to hold the sap once it's been collected.

If you make the rounds in the morning, some of the sap may still be frozen from the night before. Simply remove and discard the ice, since only the water freezes, while the sugar is left in the liquid. This is actually an effective method of concentrating sap. Also, remember that sap is a perishable substance, and if left to sit more than a day in warm weather, it will ferment and affect the quality of your syrup.

Some type of fireplace or stove will be required to boil down the sap, preferably out-of-doors or in a shed. Reducing 30 or 40 gallons of sap to a single gallon of syrup produces tremendous steam and quickly peels paint or wallpaper off interior walls. Cinder blocks work well, and an elbow of stovepipe at the back of the fireplace will help vent the smoke. A barrel stove with the top cut to fit your pan is also effective. Any metal container six or eight inches deep will do to boil the sap, though old 2' x 3' evaporating pans are common and ideally suited. The operation will require a sizable amount of wood, though scrap or slab wood from nearby mills is a cheap source of fuel.

Once you've boiled the sap down to the point where there are small bubbles, you may want to bring it inside to finish off on the stove. From here on in, the process gets a little tricky, and it is far easier to control on the kitchen range.

Boiling the sap is far easier than determining when the syrup is actually ready. The most basic method is simply to dip a wooden or cool metal spoon into the syrup. When the liquid comes off in sheets, it is considered syrup. A simple inexpensive candy thermometer makes the decision far easier, though. When the liquid reaches 219 degree F, at sea level, it is syrup, though this figure needs to be adjusted to our altitude. It's not as complicated as it sounds. Just add seven degrees to the boiling point of water. Oftentimes temperatures a little above 220 degrees will produce a syrup of fine consistency, though this figure will vary from day to day with the atmospheric pressure.

When the liquid approaches the syrup stage, it will begin to froth up the sides of the pan, and must be watched carefully to avoid messy spills. A splash of cream or dab of butter will cause the bubbles to recede temporarily. Also, skim the syrup occasionally to remove the scum formed.

The syrup should be filtered when it is finished. Commercial producers use felt filters, but cheesecloth is fine for the home operation. The liquid can be stored in any container with a tight fitting lid. Canning jars are ideal since the lids will seal properly and the syrup will stay sterile. If a light mold does form, simply skim it off and bring the syrup to boil for a minute before you serve it. Syrup is graded A, B or C according to its color and flavor, though very likely you'll find your homemade product to be far better than average.

The season should be under way shortly, although due to the record lack of snowfall during the winter of 1980, there is some uncertainty just what this spring will hold for producers. "No one can recall a year like this one, so there's no comparison," remarked Carroll County Extension Forester Peter Pohl. "There is concern that the frost, which has penetrated to 3-4 feet in some spots, may affect the season. In a normal year, snow cover would keep the frost from going down more than a foot at most in the woods," he continued. "The deep freeze may keep the trees' taproots from drawing moisture out of the soil, this limiting the sap run.

"These trees do have a tremendous capacity to conduct moisture," he added, "and while it's reasonable to assume the run may be shorter, it could well be sweeter." Less sap of a higher sugar content would translate into less boiling for more syrup. This might be just the year to start your own maple syrup experiment.