A test to check the density of boiling sap. The final test for proper density is done with a glass instrument floated in the syrup - a hydrometer or hydrotherm. When warmer weather in the late spring causes leaf buds to swell, the syrup takes on a strong molasses flavor. This signals the end of the sugaring season. Signs of a lack of vigor in any tree.
Causes are numerous and increasing.
Much research is being done on Maple decline and its possible link to environmental factors. When the sap is boiled, it is channeled down through the evaporator pan, reaching the correct temperature. An evaporator is either wood fired or as ours - oil fired. The process of clarifying pure maple syrup. Today we filter through cloth and paper membranes, producing crystal clear syrup.