A heat transfer fluid comprised of a syrup. The heat transfer fluid is comprised of by-products produced during the processing of agricultural crops such as sugar beets or corn. The heat transfer fluid is comprised of desugared molasses, condensed corn fermented extractives or corn condensed distillers solubles or any combination thereof. A method of using the heat transfer fluid to heat or cool an object. A method of using the heat transfer fluid in a heating or cooling system to heat or cool a building.