13Observe the Following Points in Canning1. Be sure the canner fits over the center of the surfaceunit. If your cooktop or its location does not allowthe canner to be centered on the surface unit, usesmaller diameter pots for good canning results.2. Flat-bottomed canners must be used. Do not usecanners with flanged or rippled bottoms (oftenfound in enamelware) because they don’t makeenough contact with the surface units and taketoo long to boil water.RIGHT WRONGFlat-bottomed canners are required for glass cooktops.3. When canning, use recipes and procedures fromreputable sources. Reliable recipes and proceduresare available from the manufacturer of your canner;manufacturers of glass jars for canning, such as Balland Kerr; and the United States Department ofAgriculture Extension Service.4. Remember that canning is a process that generateslarge amounts of steam. To avoid burns from steamor heat, be careful when canning.NOTE: If your house has low voltage, canning maytake longer than expected, even though directionshave been carefully followed. The process time willbe shortened by:(1) using a pressure canner, and(2) starting with HOT tap water for fastest heatingof large quantities of water.CAUTION:Safe canning requires that harmful microorganismsare destroyed and that the jars are sealedcompletely. When canning foods in a water-bathcanner, a gentle but steady boil must bemaintained for the required time. When canningfoods in a pressure canner, the pressure must bemaintained for the required time.After you have adjusted the controls, it isvery important to make sure the prescribedboil or pressure levels are maintained for therequired time.The cooktop surface units have temperaturelimiters that prevent the glass cooktop from gettingtoo hot. If the bottom of your canner is not flat, thesurface unit can overheat, triggering thetemperature limiters to cycle the unit off for atime. This will stop the boil or reduce the pressurein the canner.Since you must make sure to process the canningjars for the prescribed time, with no interruptionin processing time, you cannot can on any ofthe cooktop surface units if your canner is notflat enough.What is a Temperature Limiter?Every radiant surface unit has a TemperatureLimiter. The Temperature Limiter protects theglass cooktop from getting too hot.The Temperature Limiter may cycle the units off fora time if:• The pan boils dry.• The pan bottom is not flat.• The pan is off center.• There is no pan on the unit.HOME CANNING TIPSCanning should be done on the cooktop only.Pots that extend beyond 1 inch of the surface unitcircle are not recommended for most surface cooking.However, when canning with water-bath or pressurecanner, larger-diameter pots may be used. This isbecause boiling water temperatures (even underpressure) are not harmful to the cooktop surfacessurrounding the surface units.HOWEVER, DO NOT USE LARGE DIAMETERCANNERS OR OTHER LARGE DIAMETER POTSFOR FRYING OR BOILING FOODS OTHERTHAN WATER. Most syrup or sauce mixtures—and all types of frying—cook at temperatures muchhigher than boiling water. Such temperatures couldeventually harm the glass cooktop surfaces.Surface Cookware Tips Home Canning Tips