Following are questions often asked about long term storage of powdered milk for a family's supply of food:
What kind of milk is best to store? Non-fat milk, either regular or instant, stores well when packaged properly and kept at room temperature or cooler. In the past, many felt that non-instant milk would store better. There is actually no difference in shelf life between instant and non-instant powdered milk.
What are the best containers? Milk stored in airtight, low-oxygen cans has been found to last longer and stay fresher tasting than milk stored in boxes or plastic bags.
How long can powdered milk be stored? Optimal storage life on non-fat dry milk stored in cans at room temperature is two years before noticeably stale flavors begin to develop. However, when stored at cooler temperatures, it can be kept much longer. Rotation of powdered milk may be accomplished through personal use or by giving it to others who will use it promptly.
How much powdered milk should be stored? Guidelines for quantities of dry milk to store are found in the 1979 booklet published by the church called Essentials of Home Production and Storage. The booklet recommends that members store an equivalent of 300 quarts of dry milk, or approximately 75 pounds of dry milk per person per year. However, since that time, as a result of a US government study on maintaining nutritional adequacy during periods of food storage, a second option has been recommended that suggests 64 quarts, or 16 pounds per family member per year. Equivalent to approximately one glass of milk a day, that amount will maintain minimum, health standards. Keep in mind, however, that the needs of children and pregnant or nursing mothers will require more than the minimum amount of stored milk. It is recommended that families who opt to store only the minimum 16 pounds of milk per person should also increase storage of grains from the recommended 300 pounds per person to 400 pounds per person to compensate nutritionally for this change.
How can it be determined if milk is past its prime shelf life? Milk develops off-flavors as it ages. However, it still retains some nutritional value, and unless spoilage has occurred from moisture, insects, rodents or contamination, it is still safe to use.
What can be done with milk that is too old to drink? It is important to think of milk in terms of optimal shelf life rather than waiting until it is too old to use. Older non-fat dry milk can be used in cooking as long as it has been protected from spoilage. If powdered milk has spoiled, however, it can be used as fertilizer in the garden.
(Source: "Basic Food Storage Cookbook," South Jordan Utah River Stake, 2003, pg. 35)