Few things are more rewarding than preserving your own food. Despite being a neglected art, for an intrepid few food preservation can save time and money. In this post I explore the most common methods of food preservation, and the tools you'll need achieve them. While I'd hardly consider myself an expert in these matters, many of these techniques are thousands of years old and very simple to accomplish.

Before we begin, I'd like examine the primary enemies that we face when we attempt to store food. First and foremost are bacteria and fungii. These invisible microbes are everywhere, and they are hungry. They can be found in the soil, in the air, and in your refrigerator. Despite their wide presence, there are several ways to keep them from spoiling our produce. To start, we can use airtight containers to restrict air flow. Next, we attempt to make the stored food inhospitable to the microbes. We have a number of methods at our disposal: drying, pressure cooking, fermentation, or increasing acidity.

The next big enemy we face is oxidation. On the atomic level, oxidation is the loss of an electron. From our perspective it is what turns a cut apple brown, and it is what makes an open bottle of wine taste stale after several days. The primary way to reduce oxidation is to keep food tightly sealed so that no oxygen can make contact with the food. Since most plastics allow some oxygen to pass through, using glass containers is an important step towards preventing oxidation.

Once we've conquered the microbes and the oxidation, our final opponent is the rest of the food chain. This includes insects like cockroaches, and also mammalian thieves, like a rat, or a hungry roommate. Keeping your pantry clean is usually enough to prevent insects, but hungry roommates can present greater problems.

Now that we know our opponents, let's see the techniques we can use to thwart them:

	Drying Drying food is just as easy as it sounds, and can be used with fruits, vegetables, and meats. Some leafy vegetables can contain above 90% moisture, and the majority must be removed before the item can be stored at length. For leafy herbs and spices, this can be as simple as setting them outside on a sunny day. With dense items like meats, a food dehydrator can be used to speed up dehydration.
	Fermentation No discussion of food preservation would be complete without mentioning fermentation. Beer and wine are produced by yeasts in the genus Saccharomyces, which convert sugar into alcohol. Cheese and other fermented dairy products are created when bacterial cultures convert milk sugars into lactic acid. In both cases the fermentation byproducts increase the shelf life of the product. Fermentation has been invaluable to humanity. Before modern water purification, beer was the best way to provide a beverage which would not cause illness. Cheese is also a very valuable supplemental food source for climates with harsh winters. Many styles of beer and cheese can age for several years when stored properly. Wine and strong beers can last for decades!
	Curing Curing is a traditional process of preserving food using a combination of salt, sugar, or smoke. Salt inhibits bacterial growth, and removes moisture through osmosis. Beef, pork, and fish are all commonly cured meats. Among my favorites is Serrano Ham which is first rolled in sea salt, and then air-cured at 50-60F for over a year. This method is slightly different from Prosciutto which is first rolled in a layer of fat, and then cured at cool temperatures. American cured ham is generally soaked in a salt/sugar brine before being cured at cooler temperatures (below 50F), per USDA regulations.
	Canning Canning your own food might seem like a chore, but having a wide variety of stored food available in your pantry is well worth the extra effort. A few weekends of work in the spring and summer are all it takes to have a yearlong supply of canned goods. Plus, buying food that's in season is best for your body and your pocketbook. Best of all, you can start a new family tradition. Every year my family makes fruit preserves, tomato sauces, pickle relishes, and canned beans. Once you do this for a few years, you'll start to build a nice collection of glass jars. Make a few trips to your farmer's market in August and you'll find plenty of items to keep those jars filled.
	Pressure Cooking This is a technique that can be used to improve the shelf stability of your canned goods. Pressure cookers have rubber seals which allow pressure to build up inside of a closer container. As this pressure builds, microbes are killed by the intense pressure. Due to the steam that is built up by this process, pressure cookers can be very dangerous and should be used only after you have read the instructions that came with it. Before using it, make sure the relief value is clear. After using it, let the pressure drop back down to 0psi before attempting to open the container.