Long-term food storage: how to build a 3-month or 1-year supply

Two layers: a pantry you rotate, and a deep reserve

Ready.gov's emergency advice is to store at least a several-day supply of non-perishable food, and its lists cover days to a couple of weeks. A longer supply, months or a year, works best in two layers. The first is a pantry of the canned and boxed foods you already eat, bought a little extra at a time and used in rotation. The second is a reserve of dry staples, packed to keep for decades, that you dip into slowly.

For the reserve, BYU's Department of Nutrition, Dietetics, and Food Science publishes a plan whose kinds and amounts of food likely provide adequate calories and protein for an adult for one year. Our food storage calculator scales it for your household and for 1, 3, 6 or 12 months.

What to store: the staples that last

BYU's year for one adult starts with grains: about 132 pounds of wheat, 65 of white rice, 29 of rolled oats and 21 of pasta, mostly in #10 cans, and 62 pounds of legumes such as beans, split peas and lentils. Add 60 pounds of nonfat dry milk, 70 of sugar or other sweeteners, 8 of iodized salt, oils and nut butters, dried fruit and vegetables, and baking basics like baking powder and yeast.

BYU says the pounds of grains are interchangeable to suit your needs and preferences, so a family that won't eat whole wheat can store more rice, oats and pasta. It also says a source of vitamin C must be stored, because consuming less than 10 mg a day can cause scurvy within a few months; freeze-dried strawberries or vitamin C tablets cover it. Fats need storing too, but rotating often, because oils keep about a year.

Wheat is the longest-lasting grain but needs a grain mill to use. White rice is the easiest. Our bulk food storage page compares wheat, rice, beans and dry milk in #10 cans and buckets.

How to pack it: oxygen, moisture and pests

Long shelf lives depend on the packaging. Utah State University Extension says long-term packaging must prevent moisture and rodent and insect damage, and that heavy-duty plastic bags on their own aren't insect- and rodent-proof. It calls PET-and-foil pouches, sold as Mylar, exceptional food containers, because the foil layer dramatically reduces the oxygen and moisture getting through.

The usual method is to fill Mylar bags or #10 cans, add food-safe oxygen absorbers, which Utah State recommends to preserve rice quality and protect it from insects, seal them, and store the bags inside food-grade buckets. Wheat is the exception: Utah State says it doesn't need to be stored without oxygen unless insects are present. Our food storage containers page compares bags, absorbers and buckets.

• Dry foods only: grains, beans, rice, pasta, sugar, dry milk
• Mylar bags or #10 cans with oxygen absorbers
• Sealed bags inside food-grade buckets
• A label with the contents and date

Where to keep it: cool beats everything

Temperature decides how long food lasts more than anything else. Utah State says the best range is cool to moderate, about 40 to 70°F, and cites BYU research in which wheat kept acceptable quality for 25 years stored cold, in a basement, and only 5 years stored hot, in a garage or attic. It also says direct sunlight is detrimental to foods.

USDA's Food Safety and Inspection Service gives the same advice for canned and shelf-stable foods: a cool, dry place, below 85°F, and never above or beside the stove, under the sink, in a damp garage or basement, or anywhere with temperature extremes. In practice that's an interior closet, under a bed or a cool, dry basement, not the garage.

Shelf lives: why 2 years and 30 years can both be right

Published shelf lives vary widely because packaging and temperature vary. USDA's storage chart gives rice and dried pasta 2 years, low-acid canned goods 2 to 5 years and high-acid canned goods 12 to 18 months, for ordinary store packaging. BYU's estimates for the same staples in airtight, moisture-proof, low-oxygen containers run to 25 or 30 years and more.

Utah State's research fills in the middle. It says rice at a constant 70°F with oxygen absorbers will store well for up to 10 years, and in cooler storage sealed in oxygen-free containers for up to 30. Dried beans in #10 cans or Mylar with the oxygen removed keep 10 or more years, and samples stored up to 30 years still scored well with a taste panel for emergency use. Nonfat dry milk is the short one: 3 months to 3-5 years, mostly depending on temperature.

Rotate it, so nothing goes to waste

A reserve you never eat is money on a shelf. BYU suggests preparing meals one day a week using only stored food, which rotates a supply about every 7 years, and notes that food that still tastes acceptable when you open it can still be used. For the pantry layer, USDA says to check it every few weeks and use the canned goods you've had for a while, and Ready.gov says to replace expired items as needed.