Chilling maple sap helps to preserve quality, enabling producers to store sap longer and process it when convenient. This flexibility is especially helpful for part-time producers. Chilling also enables longer, more efficient boils. Research at the Cornell University Uihlein Maple Research Forest concluded that glycol chillers are an effective way to chill maple sap, maintaining freshness and reducing spoilage. The use of glycol chillers provides simplicity and lower cost in comparison to refrigerant systems. In addition, glycol chillers provide more options for chilling sap such as use of plate heat exchangers and utilizing an existing tank. Building your own chiller (Figure 1), as outlined in this document, is the most cost effective option. For more information on different methods for chilling sap and on how to select a commercial glycol chiller, see the extension bulletin titled, “Chilling Maple Sap” (Wild, 2025) at www.CornellMaple.com. It is recommended to read that document prior to this document.