AnswerLine gets questions each year about using a portable burner (hot plate) for canning. Usually the question comes when a switch has been made to an electric cooktop from a gas range or when a electric-coil range is replaced with a smooth (glass) cooktop, either radiant heat or induction, and the way of canning needs to change to prevent cracking the cooktop, fusing the canner to the cooktop, or under processing of the canned product posing a food safety risk.
Industry has answered the call for canners appropriate for induction cooktops with several options available. That aside, consumers still have valid concerns about the weight of canners and the intense heat on the surface along with scratching if the canner is slid or drug across the cooktop. When the options are beyond using the new cooktop or installing a second electric coil or gas burner range top, perhaps it makes sense to purchase a portable electric or gas burner.
Earlier this year, I, too, was exploring acceptable heat options for canning. While I have yet to purchase a new range, my 30-plus year old electric-coil range struggled last summer with the canner challenge; the struggle was sufficiently challenging to make me consider new options before getting into canning this year. In addition, I know that when I make that purchase, it will likely be a smooth electric cooktop and my pressure and water bath canners will no longer work.
The National Center for Home Food Preservation (NCHFP) offers these guidelines for selecting a portable burner for canning purposes:
– The burner must be level, sturdy, and secure. Look for enough height to allow air to flow under the burner, but not such that it will become unsteady with a full, heavy canner resting on it.
– Look for a burner diameter that is no more than 4 inches smaller than the diameter of your canner. In other words, the canner should not extend more than 2 inches from the burner on any side. For heating a typical 12-inch diameter canner, the coil must be at least eight inches in diameter.
– For electric burners, you want the wattage to be about equal to that of a typical household range large burner which is 1750W or higher. The best portable heaters found run 1500W which are deemed to be acceptable.
– You want the burner to have housing that will hold up to the high heat under the canner for long heating periods, and not damage counter tops with reflected heat.
An outdoor heat source such as a gas grill is not recommended by The National Center for Home Food Preservation for various reasons; however, a portable burner can be used outside as long as it is in a location away from wind, yet well ventilated.
In addition to advice from NCHFP, I found a lot of researched based information along with references at the Healthy Canning website.
Having read all the recommendations, I began to explore my options looking at commercial burners used in restaurants. While inexpensive, most home units are too light weight and have insufficient wattage to be considered for canning. The commercial units seemed to meet the NCFHP recommendations and received the highest recommendations from canning and restaurant users. My search narrowed to two models made/sold by the same company. One had a cast-iron burner and the other a coil burner. In the end I chose the one with a cast-iron burner knowing that it would take longer to heat and cool, but seemed to offer the most stability.
Recently my portable burner made its canning debut as a heat source to water bath a batch of raspberry jam. It worked very well for this application. The temperature was easy to control. Because the jam recipe only made four half-pints of jam, I did not use the big water bath canner so that test is still to be made as I move into canning season along with the pressure canner. Besides using the portable burner for my primary intended use of canning, it has come in handy to heat water for defrosting my downstairs freezer and keeping food warm for outdoor meals.
While not an option for me, an electric water bath canner sold by Ball® may be a good investment for water bath only canners says Karen Blakeslee, Kansas State University Food Safety Specialist. This is a stand-alone canner with its own heater/burner system much like an electric pressure cooker. It can also be used to make soups or stews. However, an electric pressure canner is not recommended by the USDA or NCHFP for canning of any sort despite information one may find on various websites.