While some foods must be processed in a pressure canner for safety, others are acidic enough to be safely canned in hot water. If you have a large enough pot to hold a few canning jars, you don't need to buy special equipment beyond an inexpensive rack to hold the jars in order to preserve food like tomato or apple sauce. Jams and jellies also preserve well in hot water.
Things You'll Need
Canning jars, lids and rings
Prepare your food for canning as indicated by a recipe.
Sterilize jars, lids and rings by boiling in water for 10 minutes. Remove the jars, lids and rings one at a time for filling.
Fill the jars with hot food and seal them with a lid and a ring.
Fill a pot half full of water and heat to 180 degrees. Load the jars into the rack and lower them into the pot. Add more water if necessary to bring the level to one inch above the top of the jars.
Bring the water to a vigorous boil, then reduce heat to let the water gently boil. At this point, start timing. A canning manual will let you know how long each food needs to processed, including additional time based on altitude.