LAKE PLACID, N.Y. — A do-it-yourself sap chilling system developed by Cornell researcher Adam Wild offers maple producers a low-cost way to keep sap concentrate cold.

The system allows sugarmakers to better control when they boil.

It repurposes window-sized air-conditioning units and picnic coolers into maple sap chillers.

A free, step-by-step construction guide is available at https://bpb-us-e1.wpmucdn.com/blogs.cornell.edu/dist/7/5773/files/2025/11/DIY-Maple-Sap-Chiller_Wild_2025.pdf.

“The flavor and quality of maple syrup are directly tied to sap quality,” said Wild, director of the Cornell University Uihlein Maple Research Forest.

Warm spring temperatures increase microbial growth, which can quickly degrade sap and cause economic losses, he said.

Chilling sap allows producers to hold it longer and boil on a more flexible schedule.

The systems use window air conditioners paired with plastic picnic coolers filled with food-grade glycol.

They were tested using either a submersible wine chilling plate in a stainless steel tank or by pumping sap through a plate heat exchanger into a 1,500-gallon insulated dairy tank.

“The glycol chilling systems proved to be a lower-cost alternative to conventional refrigeration and were extremely effective,” Wild said.

Wild estimates the cost of individual units ranges from $300 to $1,400.

The guide includes safety guidance, parts lists, cost estimates and photos.

Funding for the research was provided by the Northern New York Agricultural Development Program and the Upper Hudson Maple Producers Association.