Tapping, Collection and Evaporation Methods
Although refinements have been made in the methods of sap collection and evaporation, the fundamentals of the processes involved have remained unchanged. During late winter, temperature-induced physiological processes occur in the maples. Wounding the sapwood results in the flow of sap that can be collected and processed.
Native Americans tapped maple trees by cutting a gash in the trunk. Sap from the wound flowed through a twig or piece of bark into a birch bark or other wooden container placed on the ground. Sap from several such containers was collected and placed in a larger wooden vessel, often a hollowed out or "dugout" log. The sugar in the sap was concentrated by heating stones in a nearby fire and then placing the hot stones in the sap. The heat from the stones resulted in some evaporation and sugar concentration. Another method allowed the sap to freeze. The ice that formed was discarded, leaving behind a thick, sweet sugar solution.
Early settlers, both French and English, first followed the destructive practice of gashing maples to release the sap. The sap then was collected in wooden troughs placed on the ground. These troughs were made of short, hollowed out sections of hardwood tree trunks. Soon, an improvement over the method used by Native Americans was introduced. It involved the use of an auger to make a smaller wound or taphole, resulting in less damage to the tree. Primitive spouts, made by pushing the pith out of small stems of sumac or elder, directed the sap into the container below (Figure 2.2). Eventually, metal spouts replaced the wooden ones. The metal spout, as generally constructed, had the advantage of being a dual purpose device. It not only directed sap into a container but also suspended the container in a stable position, off the ground, by means of a built-in hook (Figure 2.3). The brace and bit (7/16") replaced the auger as the tapping tool.
|Figure 2.2. Early spouts were often made by removing the soft pith from small elderberry or sumac branches and whittling a functional shape.||Figure 2.3. A hooked metal spout used with bucket operations.|
For many years this technique continued as the preferred tapping method. Eventually power tappers featuring small gasoline motors or motors powered by portable storage batteries came into being. Motor-powered tappers are the rule today in larger operations, but smaller producers still use the brace and bit.
Collecting sap from maple trees has progressed from birch bark containers through wooden buckets and metal buckets (with covers) to the modern practice of using plastic tubing. For some time prior to World War II, a metal tubing system (known in some quarters as the gooseneck system) was in use. However, because it was prone to leaks, difficult to clean, and required strict attention to grade when installed, it did not gain general acceptance.
Before the evolution of the plastic tubing system, plastic bags were developed for collecting sap at the tree (Figure 2.4). They had several advantages over metal buckets: (1) They made it possible to see from a distance how much sap had accumulated. (2) They required less storage space between seasons. (3) Suspended as they were from hookless spouts, they could be emptied into a gathering pail by rotating them on the spout with one hand. Although they can still be purchased, an operation using them is labor intensive compared to one using tubing.
|Figure 2.4. A King maple sap bag bulging with sap.||Figure 2.5. Tractor drawn gathering tank unloading sap into dump station. The piping exiting the bottom rear of the washpan dump station transports the sap to storage tanks. Much of the collecting and transporting equipment shown in this historic picture was fabricated using lead solder. Use of equipment containing lead should be avoided in a modern maple operation.|
Initially, sap was gathered and transported by hand to the boiling site. Equipment consisted of a pair of large wooden buckets suspended from a shoulder yoke. Later, gathering was done with oxen or horses pulling a sledge or sled on which a wooden tub was mounted. Next came tractor-drawn vehicles with metal tubs or tanks (Figure 2.5). In the latter two cases, sap was carried in gathering pails from buckets at the tree and dumped into the tanks. In the 1950s, experiments began which lead to the development of pipelines and plastic tubing (Figure 2.6). By the mid-'60s these systems, transporting sap from tree to sugarhouse, were coming into general use, as was the use of vacuum pumps.
|Figure 2.6. Maple tubing showing a 2-tap harness and a lateral line. The lateral line collects sap from several trees and transports it to a mainline and ultimately to a collection tank.||Figure 2.7. Early settlers boiling sap in a large metal kettle. The long processing time, which this batch processing required, resulted in a dark syrup (Cornell University).|
Once they had gathered the sap, the early settlers boiled it down in metal cauldrons or kettles. These vessels were suspended from a pole or tripod of poles over open fires (Figure 2.7). As concentration proceeded more sap was added and the boiling continued. The resulting syrup was both strong flavored and dark. An innovation that led to improved quality was to ladle the liquid from one kettle to another as it progressively thickened.
|Figure 2.8. An early continuous-processing, wood-burning evaporator.|
This was a major improvement over the batch system used with kettles and flat pans, where boiling would take place for hours before removal of the finished syrup. The evaporator cut down the boiling time and produced a better quality product.
One of the first evaporators to be patented and used in the maple industry was the Cooks Sugar Evaporator, patented June 22, 1858. It was manufactured by Blymer, Bates, and Day in Mansfield, Ohio, and was originally made for the production of sorghum syrup. Maple producers soon tested the effectiveness of the evaporator in the manufacture of maple sugar and pronounced it without a rival. "More sugar and whiter" was acknowledged everywhere to be the result.
|Figure 2.9. A sugarhouse with a wood burning evaporator and a cupola on the roof for steam exhaust.|
In the early days, kettles for boiling sap were suspended over fires built in the open. Soon it was recognized that there should be shelter for both the sugarmaker and the product that was being prepared.
The first shelters were nothing more than crude shacks or lean-tos in the woods. Next, the settlers constructed cabin-like structures which, through the passing years, have evolved into present-day sugarhouses (Figure 2.9), many of which have electricity and running water. Some recently constructed houses, favorably situated with respect to traveled roads, not only are used for the production of syrup but also for its promotion and marketing.