Canning basics: the equipment you need to preserve your harvest

Canning fruits and vegetables has been done for centuries to preserve food to eat out of season. Canning works by heating food to a temperature that kills any existing bacteria. This heat forces air to leave the container. As the jar cools the lid is sealed on. This seal is what prevents new bacteria from getting into the food, enabling canned food to last for years.

Canning with boiling water is the cheapest way to preserve food, since it requires equipment that most people already have around the house. To start, gather together a big pot, some canning jars, bands, and lids. Typically boiling water canning is done with fruits and pickles, since it is difficult to know the exact temperature inside the jars. If the temperature inside a jar of fruit is not hot enough to kill all of the bacteria, don’t worry. Fruit has natural acids that keep bacteria from growing once the jar is sealed.

Next wash and cut the fruits and vegetables you are going to can. If you are following a recipe, use the recipe instructions for the size of the pieces. If you are not using a recipe, try to keep pieces as large as possible. This will provide you with more options for the fruit or vegetables when it comes time to use what you have canned.

Place the prepared fruits and vegetables in the jar, being careful to leave about half an inch of space at the top of each jar before you seal it. This small amount of space will allow room for the food to expand while it is cooking. Before sealing the jar, wipe the jar rim to remove food debris or salt left behind that will prevent the lid from sealing properly.

Next, heat the jar lids before placing them on the jars. To do this, heat a pot of water on the stove. Bring the lids to a simmer. Be careful not to boil the lids. Boiling can damage the rubber seal on the lid and prevent it from sealing properly. Keep the lids in the hot water until they are ready for use.

Before sealing the jar, remove any air bubbles that are trapped in the jar. The easiest way to do this is to wedge a nonmetallic spatula between the food and the jar, then looking for the air bubbles to come to the surface. If the air bubbles are not removed at this stage, they will be released while processing, and the jars will lose liquid. Thus, some of the food will be left without any covering liquid. While this will not hurt the food; the end result will not be as appealing. After checking the jar rims to make sure they are free from nicks the canning process can start.