Ladle food into sterilized jars through a wide-mouth funnel. Make sure to leave the headspace (the space between the top of the preserves and the top of the jar) specified in the recipe. If the final jar you fill isn't full, don't process it. You can cover it can keep it in the fridge instead.
5. Release Air Bubbles
Run a thin bladed knife along the inside of the jar to release any air bubbles along the sides of the jars. Wipe top edges of jars clean with a damp cloth or the jars may not seal.
6. Center Lids On Jars
When you put the lids on the jars, make sure that the sealing compound around the edges of the lids touch the rims of the jars. Screw the metal rings on firmly but not tightly and don't force them. Just screw them on so they stay in place.
7. Process Jars
Lower the jars into the boiling water (180°F to 185°F for pickles). The jars should be covered by at least 1 inch of water. Add boiling water, if needed, during processing, to keep that 1-inch buffer. Cover canning kettle to return water to a boil. Process for the time specified in the recipe.
8. Remove Jars
Lift jars out with tongs. Have a hot pad in your other hand, just in case you need to grab something. Set jars on a flat work surface. Pat dry, if you want. Don't tighten the rings, just let them sit until completely cool to room temperature. You may hear a slight "ping" from the jars as they seal. This is a good thing.