Scoop or spoon food into a sterilized, hot Mason jar. Allow 1/2 inch head space between the contents and the jar top.
Run a rubber spatula around the inside of the jar to force air bubbles out of the food and jar. Wipe the top and sides of the jar rim carefully with a damp, clean cloth or paper towel. This will remove any food residue that could prevent a good seal.
Cap the Mason jar with a clean, new lid. Move the lid into place so the rubber edge fits snugly on the jar rim.
Secure the lid with a clean metal canning ring. Screw the ring on loosely to allow steam and air to escape during canning.
Remove the Mason jars after processing the food in a canner. Don't tighten the rings. Set the hot jars on a dry cloth on a table or counter to cool.
Wait for a popping sound from each jar before removing the metal rings or bands. Run your finger across the lid after the Mason jars cool completely. A sealed jar will present a concave lid center, indicating a successful vacuum.