Think of the word convert as meaning change, whether it is a person who adopts a new belief, or a changing action, such as when you convert dollars into euros. Many times we can catch a word's meaning by looking at its origins. In this case, the Latin con means around, while vertere means turn..
Maple sap runs best when it freezes at night (e.g. in the high 20-degrees Farenheit range) and then warms up above freezing the next day (in the range of 40-degrees Farenheit and hotter). If it stays warm at night and warm during the day or if it freezes at night but barely goes above freezing the next day, sap does not flow as well or hardly at all.
11. Pour the sap collected from the maple trees into the metal can. Be sure the sap drains from the can into the roasting pan below. 12. Heat the sap to evaporate its water. Add more sap to the warming pan, as needed. 13. Frequently check the temperature of the sap with a candy thermometer. When it reaches 219 degrees F, it converts to maple syrup. It takes approximately 39 gallons of sap to produce one gallon of syrup. 14. Pour the syrup through cheesecloth, then store in sterilized bottles.