sueyin01: you been given a good answer, and then an even more robust method by Darryl1: but I'm left wondering, "why do you have to ask?" How good does the storage have to be? Most people store sucrose in their home for as long as they use it with no problem. You can gain some more shelf-life with Darryl1:'s method. But why? You could even weld it into an aseptic tin, and gamma irradiate it so it was germ-free for centuries. But who needs that?