It keeps fine in Tupperware. When it goes on sale and I buy a quantity, I store the one pound boxes or two pound bags in zippered plastic bags in the freezer and what I take out, I put in the Tupperware container, one for dark and one for light. I think each rectangular container holds about a pound. The reason I store them in plastic bags in the freezer is that sometimes there are tiny slits in the original packaging and if those went into the freezer or even were stored in a cabinet, the sugar would harden.