Food Storage Lessons

Were it not for the ability of humans to store food for future use, vast areas of the world would be uninhabitable and the food available to people in most other areas would be dictated seasonally and lack variety. Some food storage techniques are as old as human history; others are relatively new. Some techniques allow food to remain fresh and palatable for just a few days; others can allow storing food indefinitely.

Drying

• One of the oldest methods of preserving food is drying. Some foods, such as grains and some vegetables, dry naturally. Once the moisture content in the product drops to 15 percent or less, bacteria and fungus won't grow and, as long as the food is stored in a dry area, away from insects and rodents, it will last a long time. Humans have learned to dry foods, such as meat, fish, many vegetables -- even milk and eggs -- to extend their storage life.

Canning

• Canning food was perfected in the early 1800s. First done (and still done commercially at times and in homes) in glass jars, storing food in sterile metal cans or glass jars preserves almost any kind of food imaginable. Meat, fish, nuts, vegetables, drinks, soups, soap and snacks can be preserved for decades. The process consists of heating the product to the point all bacteria, spores, fungi and enzymes are eliminated, then sealing the product in a sterile can or jar. As long as the seal isn't broken, there's nothing left to degrade the product.

Cold Storage

• It has long been known that keeping food cool, cold or frozen prolongs its longevity. Bacterial, fungal and enzymatic activity slows as temperatures drop. Preserving and storing foodstuffs using winter cold gave way to using ice and eventually mechanical refrigeration and freezers. Nothing lasts forever in cold storage, but depending on the product, keeping it cold or frozen will extend the longevity of most products significantly.

Chemical

• Salt was probably the first chemical used to preserve food and is still widely used to preserve some popular food products. Other chemicals are also used. A few are naturally occurring, but others are a products discovered or created by chemists. High levels of sugar can preserve food, as in jellies and jams. High acidity, such as adding vinegar to make pickles, started as a preservative as much as for flavor. There are few commercial food products that don't rely on some sort of chemical preservative to extend their shelf life.

Combinations

• Many food products designed to be stored for significant lengths of time rely on combining two or more of the above methods to further extend their shelf life. Most canned foods are infused with salt, for flavor and to retard spoilage. Smoked meats, such as ham, bacon and fish, are often salted and dried. Ketchup, salad dressings and other foods use acidity and refrigeration to extend their usefulness as food.