Canning On a Smooth or Ceramic Cooktop
A smooth or ceramic cooktop is easy to clean and looks nice but it may not be right for home canning. For water bath canners or pressure canners to work successfully on a ceramic cooktop, the canner bottom must be flat, in contact with the cooktop and extend no more than 2 inches beyond the design on the cooktop surface. The lighter weight stamped aluminum canners usually have a concave bottom. If the concavity is greater than 1/8 inch, the canner will not perform well.
If a heavy canner is slid or pulled across the surface, the cooktop may scratch and lead to major cracking.
A food safety issue results when many ceramic cooktops have automatic shut-offs or heat-cycling when the heat gets very high. If the burner shuts off during processing, the food may be under-processed.
Many manufacturers do not recommend using a ceramic cooktop for canning. The size and weight of the pan and extended cooking times can damage the cooktop and may void the warranty if the manufacturer advises against it. Check your cooktop manufacturer recommendations.