Dehydrated foods, or simply dried foods, last much longer than if they were fresh. The shelf life of food such as beans, rice and wheat and other grains can extend up to in excess of thirty years when properly dehydrated and stored. Fruits and vegetables, normally considered very perishable when fresh or not dehydrated, have an impressively long shelf life as well. To dehydrate food, you must use a dehydrator. Their storage-period is appropriately expressed in a “best-by-date” manner. This is due to the fact that vegetables and fruits get degraded with time in terms of nutritional quality and taste. The exact date of expiration can’t exactly be pin-pointed but can only be given as an approximate for the shelf-life greatly depends on several factors as explained shortly.
Factors Affecting the Shelf-Life of Dehydrated Food
The shelf-life of dehydrated food depends on factors such as temperature, moisture content, oxygen and light.
- Oxygen concentration: oxygen reacts with some food nutrients leading to eventual spoilage. Oxygen absorbers are therefore used especially in long-term food storage containers to rid the air inside of any oxygen for optimum storage conditions thus longer shelf-life.
- Temperature: dehydrated food needs to be stored in a cool and dry place, the cooler the better. A 10 degrees Celsius drop in temperature doubles the storage shelf-life. The other way round about it is that 10 degrees Celsius which is equivalent to 18 degrees Fahrenheit increment in temperature halves the shelf-life.
- Moisture content: the lower the moisture the better since dehydration essentially involves removal of water with retention of taste and nutrients. Vegetables are ideally dried to a maximum of 5% moisture content and 20% for fruits.
- Light: reaction of light and the food nutrients breaks down fats, proteins and vitamins and lead to poor flavor and spoilage. Storing the food in the dark does the trick for longer shelf-life.
Shelf-Life of Sample Foods
The following are the shelf-lives of foods stored in the absence of oxygen, hermetically or airtight sealed and at a stable 70 degrees Fahrenheit temperature according to the USA Emergency Supply:
- Soft grains such as oats and barley, rye, quinoa and groat: 8 years
- Hard grains such as buckwheat, corn, flax, kamut, millet, wheat and triticale: 10-12 years
- Beans including black eye, black turtle, garbanzo, adzuki, great northern, kidney beans, lentils, lima, mung, pink, pinto, small red and soy beans: 8-12 years
- Dehydrated vegetables such as broccoli, cabbage, carrots, celery, onions, pepers and potatoes: 8-10 years
- Dehydrated dairy products such as cheese powder, cocoa powder, powder eggs, butter/margarine powder, powder milk and whey powder: 15 years
- Flours and cracked or ground-seed products such as all-purpose flour, bakers flour, unbleached flour, white flour, whole wheat flour, cornmeal, mixes, refried flour, cracked wheat, germade, gluten and wheat flakes: 5 years
- Pasta such as noodles, spaghetti, macaroni and ribbons: 8-10 years
- Dehydrated fruits: 5 years
- Dehydrated honey, salt and sugar: indefinitely especially if additive-free
- Peanut butter powder: 4-5 years
- Brown rice: 1-2 years and, if under normal conditions, just 6 months which is quite low since brown rice contains oils that go rancid with time
- White rice: 8-10 years
It’s of great essence to note that, much we are given the time in as a value in number of years as the shelf-life of our dehydrated food, it is a mere estimate since the actual span depends on so many factors including the condition of the food at the time you purchased it. The bottom-line, however, still holds that dehydrated food unlike fresh food lasts much longer, quantitatively to the tune of several years