I think part of it is where your thermometer is located. Mine is in my syrup pan about 10 inches from the draw off. So I start at the day drawing off at 7 into my hydrometer to confirm that my thermometer is right on for the day (or maybe a hair high or low depending on the weather). Then I start drawing off at 7 and then usually close off at 6 because my thermometer is so far away from the draw off. I think each rig is different and you will have to find what will work best for drawing syrup off.