Sugar does not 'expire' in the way that most foods do. There is nothing in sugar that will go bad or induce the growth of bacteria if kept for too long. However, there are certain conditions that can render one's sugar unusable. For instance, moisture will cause sugar to clump and harden. The biggest problem that most people encounter regarding their sugar storage is when bugs and insects find their way into a sugar stock. Sugar that has become infested with these little critters obviously cannot be used for sanitary reasons, and bug infestations often cause ridiculous amounts of sugar to be wasted and thrown away.
Thankfully, there are some methods of sugar storage that will prevent insects from entering one's sugar supply. An excellent way to repel bugs from a sugar stock is by using mothballing methods.
Mothballs are small packages of chemicals, such as 1,4-dichlorobenzene or camphor that efficiently repel insects from the area. Although mothballs are traditionally used to keep one's clothes free from mold and moth larvae, they are useful for other purposes as well, including the repelling of insects in sugar storage. For efficient sugar storage, one must first obtain a well-sealed sugar container.
Next, to prevent any bugs or insects from possibly entering the container, one can add a mothball to repel any undesired creatures. However, while the mothball must be inside the container in order to be effective, it is important that the mothball does not touch the sugar itself.
The chemicals in mothballs can be extremely toxic when ingested. Studies have shown that mothballs may even be carcinogenic. However, as long as none of the mothball's chemicals are absorbed by the sugar, this storage method should be perfectly safe. An excellent way to utilize mothballs in the storage of sugar would be to use two nesting containers. Place the sugar in the innermost container, then nest this container inside of the larger one. Next, place the mothballs inside the larger container but on the outside of the sugar container. This will repel bugs from the containers but will prevent any harmful chemicals from touching the sugar.
When it is time to remove the sugar from storage, one must simply open the containers and let them air outside for about a day before using the sugar. Upon opening the containers, one is sure to find no insects infecting their sugar storage. Mothballing is an excellent way to keep one's sugar clean and fresh.