Container Types

• The paper or cloth containers used to package bulk flour and sugar are fine for short-term storage, but they will allow spoilage and bug infestations in most pantries. Any sealable container is suitable for long-term storage as long as it is airtight and opaque, although containers made of glass, food-grade plastic and lined metal are best. Previously used containers should be thoroughly cleaned and dried before using them for flour or sugar. However, it is best to avoid containers if they retain the smell of whatever food they previously held because it may transfer to the new contents.

Light, Heat and Humidity

• Light, temperature and humidity are vital considerations because they greatly impact the quality and longevity of stored food. An airy, dark pantry with a temperature range of 50 to 70 degrees Fahrenheit is ideal, and it must have a humidity level below 60 percent to inhibit bacterial or mold growth. Storing food in opaque containers will mitigate indirect light exposure, although ambient darkness is best. Store the food away from warm areas such as ovens, hot water heaters or pipes, and monitor the temperature with an adhesive thermometer. If humidity is an issue, place desiccant packs nearby to absorb excess moisture, but keep them from touching the food because they may contain chemicals.

Potential Problems

• The correct storage conditions and containers will minimize the chance for spoilage in bulk flour and sugar. However, no amount of preparation can completely eliminate the potential for pest infestations. Bugs such as meal moths and pantry beetles seek out flour and sugar, contaminating them with their excrement, eggs and body parts. Keeping a clean pantry will decrease their numbers, while using tightly sealed containers will keep the bugs out. Pheromone traps will capture and eliminate any prowling pests, although they are only effective for a limited time and must be replaced every three months.

Storage Tips

• Even under ideal conditions, the quality of bulk flour and sugar will eventually degrade. It is best to use the staples slowly over time to keep a rotating stock of fresh ingredients. Keep the containers labeled with the date of purchase and use the older flour and sugar first to prevent it from spoiling. Always smell the ingredients before cooking with them, and inspect them for signs of pests such as sticky or cottony matter, black flecks or visible insect parts. Any flour or sugar with signs of bugs or an unpleasant, sour smell should be discarded and the container should be thoroughly sanitized before reusing it.