Why are your canning jars cracking when the hot food are placed in them?

The most common reason for jar breakage is thermal shock. Either you are putting cold food into hot jars, or hot food into cold jars, or cold jars into boiling water.

To prevent jars breaking when putting them into a water bath, begin by washing your jars in hot water. If the water in your sink is not too hot for your hands, it will not shock the jars. After rinsing, put them immediately into the water bath and fill it over the top of the jars with hot tap water. Bring the jars to a boil and let them remain there for 15 to 20 minutes. Afterward, turn off the heat, and let the jars remain in the water bath until you are ready to fill them. Fill hot jars with hot food. lid and ring the jars and return them immediately tot he water bath (if you are hot bath canning--if you are pressure canning, put the jars into the pressure canner rack and fill the canner with hot water after the jars are all in place. (DO NOT PUT COLD WATER OVER HOT FILLED JARS).