“This project has value for maple producers statewide. The flavor and quality of maple syrup is directly related to sap quality,” Wild said. “The ability to chill and hold sap prevents spoilage and adds flexibility for producers to boil sap at their convenience, particularly for those maple producers who also operate dairy farms or have off-farm jobs.”

To build the chillers, Wild adapted window-size air conditioning units and connected plastic picnic coolers holding a food-grade glycol solution. The units were tested in combination with either a submersible wine chilling plate in a stainless steel tank or pumping sap from a reverse osmosis system through a 20-plate heat exchanger and a 1,500-gallon insulated dairy tank with its own cooling plates. The Upper Hudson Maple Producers Association provided the dairy tank for the testing.

“The use of glycol chilling systems can be a less expensive alternative to refrigeration for keeping maple sap cool,” Wild said. “The chillers built for this project were extremely effective, providing efficiency in processing the sap at Uihlein with 40% less boiling and saving more than 24 hours of labor for post-boil cleanup.”

Wild estimates the cost to build the individual chiller units at $300 to $1,400.

As a Northern New York Agricultural Development Program-funded proof-of-concept project, Uihlein Maple Research Forest Director Adam Wild built DIY food-grade glycol chillers to cool maple sap in sap holding systems large and small. Pictured above is a DIY glycol chiller connected to a chilling plate in a small tank. (Provided photo — Adam Wild)

The “Chilling Maple Sap” bulletin includes information on the cooling efficiency of food-grade glycol, freezing points and how to size a DIY or a purchased chiller to fit different maple operations.

The “How to Build a Maple Sap Chiller” DIY step-by-step guide by Wild includes safety tips, a parts list, costs, photos and optional add-ons. An added convenience option noted in the how-to guide is the use of Wi-Fi access for remote monitoring and control of the sap chilling system.

Wild, who is also co-director of the Cornell Maple Program, is continuing the use of the DIY units at the Uihlein Maple Research Forest in Lake Placid. The informational bulletin and how-to guide are posted at nnyagdev.org and available from the Cornell Maple Program.