How to Pressure Can:
You will want to thoroughly wash your produce in order to get rid of any chemicals and dirt (a large colander is helpful during this step). If you are preparing rough root vegetables you may want to use a scrubber brush to get all of the dirt off. Bruised and moldy fruit should be thrown out, as micro-organisms have started to grow on them (and that is something you want to avoid adding to your preserves). If your fruit just has surface blemishes or imperfections then it is still okay to use.
Unless the recipe calls for peeling the fruit or vegetable, you will want to leave the peels on because some peels contain valuable pectin, which helps to thicken the end product.
Now that you have your produce prepared you will want to read through the canning recipe you are using and set out all your ingredients. And always remember to get all your measurements as accurate as possible!
Be sure that all your canning tools are available and ready to use, lay them all out before you start canning. With them laid out check your tools over to be sure that they are in good condition. Check the gauge and gasket on your pressure canner and be sure that your jars do not have nicked edges. These things can cause bacteria growth in your food leading to spoilage.
Double check the tops for your jars, be sure that you have enough vacuum caps and lids for the amount of jars you are preparing. Be sure that your vacuum lids are new and do not have any rust on them. The screw bands will also need to be free of rust. If you are using another type of lid, check them over thoroughly. Also be sure your lids fit your jars before you begin filling your jars with food.
Be sure that all your equipment is clean and that your pressure canner's gauge has been check in the past year.
Follow the instructions for the type of canning jar lid that you are using for your canning. Some jar lids differ in how they should be handled before the canning process begins.
There are two different methods of packing food into canning jars. These two methods are raw pack and hot pack. (Your recipe should tell you which method is preferred).
Raw Pack: packing raw, prepared food into clean, hot jars and then adding hot liquid. Most vegetables and fruits need to be packed tightly because they will shrink during processing. Raw corn, Lima beans, and peas should be packed loosely as they tend to expand. Since the processing in raw-pack can sometimes shrink foods, some foods will float to the top of the jar.
Hot Pack: heat prepared food to boiling or partially cook it. Food should be packed loosely, while still boiling, into clean, hot jars. This method is usually used with firm foods that process well. During the precooking phase of the hot-pack method, the food breaks down and this eliminates air so that the food is much less likely to spoil and it will not float in the jar. With this method more produce can be loaded into fewer jars and the canning time decreases since the food is already hot.
For either packing method, pack high acid foods, including acidified tomatoes and acidified figs, to within 1/2 inch of the top of the jar. Low acid foods need to be packed to within 1 inch of the top of the jar.
Measure Your Headspace: The space in the jar that is between the top of the food or liquid and the inside of the lid of the jar is known as headspace. A general rule of thumb is to leave 1/2-inch headspace for high-acid foods, fruits, tomatoes, pickles, and relishes; 1-inch for low-acid foods, vegetables, and meats; and 1/4-inch headspace for juices, jams, and jellies. Be sure to use care in filling your jars to the correct headspace.
Remove Air Bubbles: If there are air bubbles present after the food has been packed into the jar, then they need to be removed. You can do this by using a plastic spatula inside the jar (or a bubble remover/freer). (Metal utensils are not recommended since they can damage the glass of the jar). Press the spatula back against the food to release any air that may be trapped. Repeat this several times around the interior of the jar. Even though air bubbles may not be visible, they could be trapped between pieces of food and must be removed.
Clean the Jar Bands, Lids, and Rims: Double check that your bands and lids are clean, also you need to wipe the rim of the jar with a clean, damp cloth. This is to ensure there isn't any food on the rim of the jar that would prevent a vacuum seal.
Adjust Lids and Bands: After filling the jar and cleaning the rim, place the lid on the jar rim. Center the sealing compound on the glass (only this part should be touching the glass). Place the band over the lid and screw down until it is fingertip-tight. You will want it to be snug and firm, but not as tight as you can get it. Now get out your jar lifter and place the jar onto the canner rack inside your pressure canner.
Place your canner rack in the bottom of your pressure canner. Add about 2 inches of water (or what your canner's instructions advice to be added). Heat water to a simmer. Prepare your recipe. Fill jars and adjust lids.
As soon as each jar is filled, place them on the canner rack. Lock the canner lid into place securely. Leave the weight off of the vent-pipe or open petcock (this step depends on the type of pressure canner you have). Adjust the heat to medium-high setting until steam flows evenly from the petcock or vent pipe. The steam will need to be exhausted from the canner for 10 minutes.
Close the petcock or place your weight onto the vent pipe. The canner should pressurize in approximately 5 minutes. After the gauge indicates that the recommended pounds of pressure has been reached, you will need to adjust the heat to maintain pressure for the entire canning period. Set your timer according to the processing time stated in your recipe.
After the processing period is complete, turn off the heat. You will need to allow the pressure canner to cool naturally. Do not remove the weighted gauge or open the petcock until the canner has depressurized and returned back to 0 pressure. Once at 0 pressure you can open your petcock or remove your gauge. Let the canner cool for 10 more minutes before removing the lid. Unlock the lid and lift it off of the canner base, be careful that the steam escapes away from you and not towards. Let the canner cool for another 10 minutes before removing your jars.
Remove your jars from the pressure canner. Set the jars upright on a dry towel or a cutting board to let them cool. Leave 1 to 2 inches of space in between your jars. Do not tighten bands if they loosened during processing. Let jars cool naturally 12 to 24 hours before checking for a seal.