Collecting the watery sap, by one means or another, from maple trees and evaporating it to make syrup has a fairly long history. Documented records give early accounts of the practice from back in the middle 1500s in North America. People have devised various means for tapping the trees but one well established tradition entails making a tree tap, or spile, from the stems of the elderberry shrub.
Identifying the elderberry shrub is an important step in making the tree tapping spile. In the growing season, elderberry has compound leaves. This means each leaf is divided into separate leaflets. Leaves are attached along the stem opposite each other. When flowering, elderberry has umbrella-shaped clusters of creamy white flowers. These produce clusters of deep purple, almost black fruit in late summer. In the winter, scars where the leaves were attached at intervals on opposite sides of the twigs are visible. And the elderberry twigs have a warty texture.
The ideal finished spile diameter is about 1/2 inch. This means the rough stem, as a starting point, should be somewhat larger. There's the outer bark and an inner bark layer that must come off before the spile is ready to use. Other considerations are straightness and stem integrity. A crooked stem is going to be less than ideal, and a section of stem with decay is not going to make a good spile. So it's mostly common sense, but attention to detail in stem selection will make a significant difference in the outcome.
Once the stem is selected and cut it must be hollowed out to make the spile. The centres of elderberry stems are relatively spongy. This makes hollowing the stem fairly easy. Holding the piece in a vice or by other means firmly but gently enough to avoid crushing lets you hollow out the centre.
Drilling a hole, or lumen, down the centre of the spile is probably the easiest and safest way to hollow out the spile. A power drill or hand drill and an 1/8-inch drill bit will do the job. The drill hole should be about 3 inches deep. Keep in mind that the spile will be conducting a liquid that is intended to be consumed. So avoid letting the spile come in contact with drill bits or other material that may have toxic solvents, lubricants or other toxic chemical residues.
Whittling is going to be much easier if the elderberry stem is cut to a length of several times its intended finished length. The excess can serve as a handle for grasping while whittling and can be cut off after the whittling is completed. A good, sharp knife will take off the outer and inner bark, and enough wood to achieve the desired diameter of 1/2 inch. Shaping the end of the spile with the whittling knife so it has something of a spout will almost finish the job. The only thing left to do is to cut off the excess length.
Using the spile requires drilling an approximately 2-inch-deep hole at a slightly upward angle using a 7/16-inch drill bit. After the tap hole is cleared of drilling debris -- using a small twig or the like -- the spile is ready to be inserted. Tapping it in gently with a wooden mallet will make for a good, snug fit. Remember that since the spile is whittled to be slightly oversized in diameter, it may be necessary to do some slight shaving to make the final fit. Driving in a nail or a screw above the spile and hanging a suitable collecting container completes the tapping process. Then it's just a matter of waiting for the container to fill with sap.