Storing Granulated Sugar
Granulated sugar should be stored in an airtight container in a cool, dry place. This sugar can get hard and lumpy if it takes on moisture.
Granulated sugar, properly stored, has a very long shelf life (multiple years) because it does not support microbiological growth. However, for best results, we recommend using your granulated sugar within 2 years of purchase.

Storing Powdered Sugar
Powdered sugar should be stored in a cool, dry place away from odors, as odors can be absorbed through the packaging. It can be stored in its unopened package, in an airtight container, or in a sealed plastic bag.
For best results, use powdered sugar within 2 years of purchase.

Storing Brown Sugar
Store your brown sugar (light and dark brown) in a way that retains its natural moisture. Use the original packaging (closed tightly) or place the sugar in a moisture-proof container.
For best results, use brown sugar within 2 years of purchase.

If your brown sugar hardens, let it stand overnight in a sealed jar or container with a slice of ordinary white bread, a damp paper towel, or an apple slice. The brown sugar will reabsorb some moisture and become significantly less hard. For a quicker fix, heat the needed amount of brown sugar in a 250°F oven for a few minutes. Alternatively, put 1 cup of water in a microwave along with your opened bag of brown sugar and microwave on low for 1–2 minutes per cup of sugar. Use this sugar immediately after microwaving.