Freeze-dried food

• It's light. Most of the water is removed, so a month of food fits in a closet.
• It lasts. Many brands advertise 25 to 30 years for sealed cans and pouches stored cool.
• It tastes close to fresh, especially fruit, meat and vegetables.
• It's ready fast. Add water, wait, eat.

This is the big one. Many kits count a "serving" as 100 to 250 calories. A kit sold as "a 30-day supply" might only give one adult 1,000 to 1,500 calories a day. That's not enough to live on.

1. Ignore servings. Look for total calories in the kit.
2. Divide total calories by 2,000. That's how many adult-days it really feeds.
3. Divide the price by those days. Now you can compare brands fairly.
4. Check protein and sodium too. Some entrées are mostly pasta and salt.

Freeze-dried entrées are the most expensive way to store calories. The best long-term pantries mix three things:

• Bulk staples for cheap calories: white rice, beans, oats, wheat, sugar, salt and oil.
• Freeze-dried fruit, vegetables, meat and dairy in #10 cans, for nutrition and real cooking.
• A smaller stash of complete freeze-dried meals for grab-and-go, travel, or days when cooking isn't possible.

• Keep it cool, dry and dark. Heat shortens shelf life more than anything.
• Store off the floor, away from pests.
• Once a #10 can is opened, put the plastic lid on and use it within months.
• Write the purchase date on every can and bucket.
• Rotate: eat the oldest when you go camping and replace it.

Home freeze dryers let you preserve garden harvests, leftovers, eggs, dairy and full meals. They cost a few thousand dollars, a batch takes about a day or more, and they need a vacuum pump, a ventilated spot and some noise tolerance.

• Seal finished food in Mylar with oxygen absorbers, or in jars for shorter storage.
• Foods high in fat or sugar don't store as long.
• It pays off most for big gardens, hunters and large families.