Screw adjustment on back allows for micro adjustments. The temperature at which water boils changes according to altitude and atmospheric pressures, so you will calibrate the thermometer in boiling water before you begin boiling your sap each day. Simply turn the micro-adjustment screw to “0” when the thermometer is in boiling water. Then insert the thermometer into your pan’s thermometer port. The arrow will make one full revolution and land on the bold “7” marker when the syrup is ready to draw off.
We also offer thermometers with a 0–250ºF scale which are excellent for bottling.