Freeze-Dried Foods

Freeze-drying takes the water out of cooked food at low temperature under vacuum, which leaves the shape, the flavor and most of the nutrition and removes the one thing that spoils it. Sealed in a #10 can with an oxygen absorber, it keeps 25 to 30 years. It's the most convenient long-term food there is and the easiest to buy badly, because the can is sold by servings and a serving is whatever the label says it is. The number to read is calories.

#10 cans over pouches for the deep store; pouches are for the bag, and their rated life runs from 5 to 30 years depending on the maker and the film. Buy single ingredients, meat, vegetables, fruit, eggs, cheese, over complete meals when you can; they are cheaper per calorie, more flexible and have no seasoning to tire of. Do the math on every can: total calories in the can divided by the price is the only comparison that holds up. A can that says 25 servings and 2,500 calories is a day and a quarter of food for one person, not a month. Then buy what the family will eat; open one can and cook from it before buying a case.

Cool, dark and dry, cans upright and off the floor, because the can is the whole barrier and a rusted or dented can has lost it. Heat is the enemy of the 25 years: a can in a garage at 90°F loses years for every summer. Once opened, press the plastic lid on and keep it dry; the food pulls moisture from the air the moment the seal breaks, which is why an opened can of meat or eggs is a few weeks and an opened can of fruit is a year.

The can first: a bulge, a puncture, a seam dent or rust through the metal means the barrier failed and the contents are suspect. Inside, freeze-dried food should be dry, light and crisp; clumping, softness or stickiness means it has taken on moisture. An off, rancid or stale smell in a fatty food (meat, cheese, eggs) means the oxygen got to it. Faded color alone is age.

Rehydrate with roughly equal volumes of water for most foods, hot for cooked food and cold for fruit, and wait 5 to 15 minutes. It takes about a cup of water per cup of dry food to come back, which puts it on the water budget: a family living on freeze-dried meals uses a gallon or more of cooking water a day on top of drinking. It cooks with no fuel beyond heating water and no skill, which is the case for it in the first weeks of an outage; the case against it's cost, which is why the buckets of grain and beans carry the months after. The Survival Foods field guide has the full stockpile plan.

Hot water is all it needs, and cold water works for most of it given time. Count the water. An opened can in a warm house goes faster than the table says; eat from an open can every day until it is empty rather than opening several.

Shelf-life figures are from the Survival Foods field guide; fridge, freezer and pantry times are from the USDA cold and pantry storage charts. Run the look, smell, taste check before eating anything past its date.