With Mountain House products on hand and a one-burner stove or candle to heat water (cold water can be used in a pinch), you can still enjoy a hot, satisfying meal in less than 10 minutes. #10 Cans have the longest shelf life available...up to 25 years! Each can is coated with a protective enamel inside and out for double protection, including the lid. The cans contents are protected until you are ready to open and use them. After opening, it is recommended that you use the contents with 2 to 3 weeks for best results and taste; using the convenient resealable plastic lid between uses. Treat any leftover food as you would fresh food. Mountain House freeze-dried foods are packed in airtight NITROGEN PACKED #10 cans or pouches. Up to 98% of the residual oxygen has been removed. Mountain House's unique canning process uses both vacuum oxygen removal and nitrogen flushing.