Long-Term Food Storage: What Lasts, and What Decides How Long

By GoldBlock WorkshopPublished Updated

The short answer

Dry staples such as white rice, wheat, oats, dry beans, sugar, salt and dried milk can keep for many years, but only if they stay cool, dry, dark and sealed away from oxygen and pests. Temperature decides most of it: in one Brigham Young University study, wheat kept acceptable quality for 25 years in a cool basement and only 5 in a hot garage or attic. Pack dry food in oxygen-barrier containers (Mylar-type bags, #10 cans, PETE bottles or glass), protect it from rodents, label it, and rotate it into your everyday cooking.

Key numbers

Where long-term storage fits

Long-term storage is the slow layer of a food plan: staples you buy in bulk, pack once, and draw down over years. It works best underneath a rotating everyday pantry (Home Food Store and Rotation), not instead of it.

What stores well for years

Utah State University Extension’s packaging guidance covers barley, brown and white rice, canned goods, dried beans, dried eggs, dried fruit, dried meats, dried milk, dried vegetables, fats and oils, MREs, oats, spices and seasonings, sugars, vitamins and wheat. They do not all last equally:

  • The long keepers are dry, low-oil staples. USU: “When properly sealed and stored, polished white rice will store well for 25 to 30 years”; a BYU study “sampling polished rice and parboiled rice stored from 1 to 30 years” found both kept their nutrients and flavor. USU on wheat: rotate it “so that no stored product is older than 5 years.”
  • Shorter keepers in ordinary pantry packaging, from North Dakota State University Extension’s storage chart (FN579, reviewed January 2023): whole wheat flour 3 to 6 months unopened, vegetable oil 6 months unopened (3 to 5 months opened), brown rice 1 to 2 years, nonfat dry milk 3 months. USU’s oxygen-absorber guidance: “Products that are low in moisture and oil are best for use with the absorbers.”
  • Commercially canned food keeps 2 to 5 years for low-acid foods and 12 to 18 months for high-acid foods (USDA; home-canned food is best used within about a year, NCHFP), and belongs in your rotating pantry. USDA notes that temperatures over 100°F are harmful to canned goods.

The nutrition target the store is measured against is in Food and Nutrition Requirements.

The five things that decide shelf life

The USU pages name temperature, moisture, oxygen, light and pests.

  1. Temperature. USU: “The optimal temperature range is in the cool to moderate range, approximately 40 - 70 degrees F”; for grains, “Storage at 40-60°F is optimal for most home stored grains,” and “Storage at temperatures above 60°F causes a more rapid decline in seed viability”; “vitamin breakdown rates in all stored foods will increase as the temperature increases.” For rice, “The best temperature to store grains, including rice, is 40°F or below.”
  2. Moisture. USU: “A moisture level more than 12% encourages mold growth and chemical degradation of all grains”; “The humidity in the storage environment should be low”; moisture “can also lead to the breakdown of some packaging materials (paper degradation and metal rusting).”
  3. Oxygen. USU: an oxygen-free atmosphere “will kill adult insects and prevent larval insects from surviving”; plastics “will allow significant oxygen levels into the container in 1 to 2 years.” Oxygen absorbers in a true oxygen-barrier container remove it; see Mylar Bags and Oxygen Absorbers.
  4. Light. USU: “Direct sunlight is detrimental to foods. It can speed deterioration of both the food and the packaging.”
  5. Pests. USU’s insect control guidance for wheat is below; rodents “can easily chew into” even a foil-layered bag (USU, on MRE pouches).

Containers that work

USU’s absorber fact sheet: “Use absorbers with metal cans, foil pouches, PETE plastic bottles and glass canning jars,” and “Oxygen will permeate plastic over a period of time,” so buckets are lined with Mylar.

  • Mylar-type foil pouches. USU: PETE “and foil laminate pouches are exceptional food containers”; “The foil layer dramatically reduces the transmission of oxygen and moisture through the film”; the inner layer “is food-grade plastic with no known toxicities.” On rodents: “even though there is a metallic layer in the bag, rodents can easily chew into it.”
  • #10 cans, sealed with a can sealer. USU (Packaging Foods, Fats & Oils): “Metal cans are the most resistant to long-term oxygen transfer”.
  • PETE plastic bottles “can be used with oxygen absorbers to store bulk dry foods” (USU): only bottles previously packaged commercially with food, with screw-on lids that have plastic (not paper or foam) seals, washed, rinsed, drained and dried.
  • Glass canning jars work well for smaller amounts kept in the dark, provided a tight-sealing lid is used (USU).
  • Food-grade buckets. USU’s absorber guidance: “Oxygen will permeate plastic over a period of time,” and lining a bucket with Mylar reduces this. USU on wheat: “Wheat stored in ~10 pound bags is easy to manipulate,” and “Several bags can be placed inside a 5-gallon plastic bucket.”

Label every container with the contents and the date it was packed.

Pest control for stored food

USU’s guidance for stored grain:

  • Prevention first: “Choose insect-free sources for wheat. Store them in clean and dry containers impermeable to insects.”
  • Oxygen absorbers: an oxygen-free atmosphere “will kill adult insects and prevent larval insects from surviving.”
  • Freezing: “Freezing kills live pests, but not insect eggs.”
  • Dry ice: “Dry ice will control most adult and larval insects present, but usually will not destroy eggs or pupae.”
  • Not recommended by USU: insecticides (“may be toxic if not correctly used”), heating (“too difficult to control the correct amount of heat to apply”), and bay leaves, nails or salt (“these have absolutely no effect on insects or insect eggs”).
  • Rodents: USU says rodents “can easily chew into” a bag even with a metallic layer; rigid containers are the barrier.
  • Cleaning up after rodents (CDC): “Open all doors and windows for 30 minutes before cleaning to ventilate the space.” Leave the space while it airs out. Wear rubber or plastic gloves, spray droppings and urine with 1 part bleach to 9 parts water and let it soak for 5 minutes, then wipe up with paper towels, disinfect the surrounding surfaces, wash your gloved hands, take off the gloves and wash your hands with soap and water. “Don’t vacuum or sweep rodent urine, droppings, or nesting materials.” Follow CDC’s full cleanup steps (linked below).

Storage food safety

USDA and the CDC give the signs that stored food is to be thrown out: off odor, flavor or texture, leaking, bulging or badly dented cans, and contact with floodwater.

  • Inspect before use. USDA: “Spoiled foods will develop an off odor, flavor or texture”; the CDC: “Never taste food to know if it is safe to eat,” and throw out food that may have touched floodwater.
  • Cans: USDA: “Never use food from containers showing possible botulism warnings” (USDA names “leaking, bulging, or badly dented cans”); discard deeply dented cans (“one that you can lay your finger into”) and any can with rust inside.
  • Dates: USDA: “Except for infant formula, dates are not an indicator of the product’s safety”; “Do not buy or use baby formula after its ‘Use-By’ date.”
  • Never pack moist food in low-oxygen packaging. USU: “Storing foods with high moisture content in reduced oxygen packaging may result in botulism poisoning,” and “Foods should be below 10% moisture content for storing with absorbers”; see Mylar Bags and Oxygen Absorbers.

Keeping fresh produce long term

Fresh roots and produce are a different kind of storage, with each crop’s temperature and humidity figures from extension sources, covered in Root Cellars and In-Ground Storage.

Common questions

How long does stored food really last?

USU: properly sealed polished white rice “will store well for 25 to 30 years,” and at a constant 70°F with oxygen absorbers “for up to 10 years.” Wheat “retained an acceptable quality for 25 years stored cold (basement) and only 5 years stored hot (garage or attic)” (BYU research reported by USU). A label’s 25-year claim is the maker’s figure for its own stated conditions.

Do I need oxygen absorbers?

USU: an oxygen-free atmosphere “will kill adult insects and prevent larval insects from surviving”; absorbers are used “with metal cans, foil pouches, PETE plastic bottles and glass canning jars” and with foods “below 10% moisture content.” USU also notes that for wheat “It is not necessary to store wheat in the absence of oxygen unless insects are present.” See Mylar Bags and Oxygen Absorbers.

Are plastic buckets enough by themselves?

USU: “Oxygen will permeate plastic over a period of time,” and plastics “will allow significant oxygen levels into the container in 1 to 2 years”; lining the bucket with Mylar reduces this.

Can I store brown rice or flour long term?

NDSU’s pantry chart gives brown rice 1 to 2 years and whole wheat flour 3 to 6 months unopened, against USU’s 25 to 30 years for sealed polished white rice; USU’s absorber guidance says products “low in moisture and oil are best for use with the absorbers.”

Where should I keep long-term storage?

USU: approximately 40 to 70°F, low humidity, out of direct sunlight; “Storage at 40-60°F is optimal for most home stored grains.” In the BYU wheat finding, the cold basement gave 25 years and the hot garage or attic 5.

Where to go next

Sources