Answer:
Heat till the liquid boils, if you just want the sugar.
If you want both, perform simple distillation, you must put the sugar in a flask, put a flame under the flask, and attach a tube to the flask (must have an airtight fit). Then attach a liebig condenser to the tube, and a receiving tube to the end of the liebig condenser. Have a flask under the receiving tube to collect the liquid. What will happen, as you heat the mixture is: all the liquid will evaporate, go along the tubes, and condense at the liebig condenser back into liquid, and it will dribble into a flask. The sugar will be left in the original flask. Getting both of them is more complicated than getting just the sugar :)