For both 1/2-pints and pints, add 5 minutes processing time for altitudes between 1,001 to 6,000 feet elevation and 10 minutes processing time for altitudes above 6,000 feet elevation. High-acid foods such as fruits, pickles, sauerkraut, jams, jellies, marmalades and fruit butters with a pH level of 4.6 or lower can be preserved by boiling water canning (low-acid foods, such as canned meats and fish, require a pressure cooker). Boiling water canning makes use of a large pot that’s tall enough to fully submerge canning jars by at least an inch of water. The pot is used for both sterilization of jars prior to filling and for boiling the jars once they are filled. You don’t necessarily need to purchase a boiling water bath canner if you don’t already have one. Any large, deep stockpot equipped with a lid and a rack can double as a boiling water canner. Keep in mind: The pot must be large enough to fully surround and immerse the jars in water by 1 to 2 inches and allow for the water to boil rapidly with the lid on.