Canning Using The Stove Top

The pot must not be more than 1 inch wider than the heating element. Another problem is that canners that exceed the burner diameter by more than 1 inch can trap and reflect heat to surfaces of the stove that are not intended to get that hot, and thus crack the stove top. The damage can range from discoloration of white tops to actual burner damage to cracking of the glass tops to fusion of the metal to the glass top.

*Avoid dragging. Scratching of the stove surface can occur if the canner is slid or pulled across the cook top. This often happens with large, heavy filled canners, so people need to be careful.

*Auto-shutoffs prevent sufficient heating. As mentioned above, many of these cook tops have automatic cut-offs on their burners when heat gets excessive. If that option is built in, and the burner under a canner shuts off during the process time, then the product will be under-processed and cannot be salvaged as a canned food. The process time must be continuous at the intended temperature, or microorganisms may survive. Also, if the pressure drops quickly, most likely liquid and maybe even food will be lost from the jar (it will spill over from the area of higher pressure inside the jar to the lower pressure now in the canner around the jar).

*Use flat-bottomed canners.  Even if boiling water canning is approved by the manufacturer, it may be necessary to fashion your own canner out of a very large flat-bottomed (smooth) stockpot with a bottom rack inserted. Many canners do not have flat enough bottoms to work well on a smooth cook top to be able to maintain a full boil over the tops of the jars. The pot used as a canner must also be large enough to have lots of water boiling freely around the jars, and at least 1 inch over the tops of jars. If the canner is too small, then it starts boiling faster than expected and the total required heat the jars receive in the canner even before the process time begins can be too short.