Mountain House® freeze-dried foods are packed in airtight NITROGEN PACKED #10 cans. Up to 98% of the residual oxygen has been removed. Their unique canning process uses both vacuum oxygen removal and nitrogen flushing. This is a time consuming and slightly more costly process…but well worth it. It is the same process mandated by the U.S. Military for whom they also can. Their foods will have the longest shelf life available…up to 30 years! Each can is coated with a protective enamel inside and out for double protection, including the lid. The can contents are protected until you are ready to open and use them. After opening, they recommend using the content within 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.