You can preserve food by water-bath canning, pressure canning, freezing, or dehydrating—all are time-honored and safe techniques. Canning and preserving are great ways to save foods at their peak freshness and flavor and to stock your pantry with nutritious and delicious fare. These checklists provide quick instructions for each food preservation method, information on how to adjust recipes for high-altitude processing, advice to ensure canning success, and details on must-have canning and preserving equipment.

Like cooked food, canned food is subject to changes in appearance and nutritional content. Food is canned by heating what goes into the container and then sealing the container to keep out air and microbes. It is then reheated after the can/jar is sealed. Heating food often changes its color and texture. It also destroys some vitamin C.

Water-bath canning, sometimes referred to as the boiling-water method of canning, is the simplest and easiest method for preserving high-acid food. Water-bath canning destroys any active bacteria and microorganisms in your food, making it safe for consumption at a later time. Prepare equipment and utensils. Examine the jars for nicks or chips, the screw bands for proper fit and corrosion, and the new lids for imperfections and scratches.

Whether you can food yourself or buy it canned, canned food has the potential to spoil. To avoid making yourself sick with canned foods that have spoiled, watch out for these signs of a spoiled product: A bulging can or lid, or a broken seal A can or lid that shows signs of corrosion Food that has oozed or seeped under the jar’s lid Gassiness, indicated by tiny bubbles moving upward in the jar (or bubbles visible when you open the can) Food that looks mushy, moldy, or cloudy Food that gives off an unpleasant or disagreeable odor when you open the jar Spurting liquid from the can or jar when you open it Botulism poisoning can be fatal.

To can low-acid foods, you use a pressure canner. Pressure canning is the only safe way to can low-acid foods. Each step of the pressure-canning process is important to produce safe, home-canned foods: Assemble your equipment and utensils. Examine the jars for nicks or chips, screw bands for proper fit and corrosion, and new lids for imperfections and scratches.

Pickling preserves food in a brine solution. The perfect balance of salt, vinegar, water, and herbs and spices can safely preserve your pickled food. You can achieve this balance by precisely measuring your pickling ingredients: Salt: Used as a preservative. It adds flavor and crispness to your food, especially pickles.

Preventing food spoilage is the key to safe canning. Over the years, home canning has become safer and better. Scientists have standardized processing methods, and home canners know more about using these methods. When you follow up-to-date guidelines exactly, you don’t have to worry about the quality and safety of your home-canned foods.

Home cooks who live at high altitudes may be used to adjusting recipes; high-altitude adjustments apply to home canning, as well. Canning food safely requires your filled jars to be processed at a specified temperature or pressure level for a specified amount of time. If you live at altitudes higher than 1,000 or 2,000 feet above sea level, adjust your canning recipes for food safety.