Research into Designing a Walnut Specific Spile
During the 2019 sap season, Future Generations University, with funding from the West Virginia Department of Agriculture, began a series of tapping studies on tree species other than maple. We tapped and made syrup from black walnut trees. We had trouble developing the expected natural vacuum on the 3/16-inch lines, even though they had plenty of slope. We assumed that the problem was related to vacuum leaks associated with a poor seal in the soft wood with the minimally tapered spouts.