What are some potential safety issues with these types of devices?
A large issue is the lack of ability to confirm that the canner is operating at the correct pressure, since it does not have a dial or weighted gauge. These gauges measure the pressure by physical forces acting on the gauge, while electric canners rely on a digital sensor to control temperature — there is no way to verify that the device is actually at the right temperature. A second potential issue could be the heat up and cool down time, which may differ from a standard canner due to it being made of different materials. Lab testing has shown that all stages of processing contribute to the destruction of microbes, with the greatest number of bacteria being killed during the cool-down phase of canning. (https://extension.psu.edu/use-validated-recipes-to-preserve-foods)
Why is an electric water bath canner safe to use?
With the water bath canner, you can very easily observe that the water is boiling, just like with a standard water bath canner. As long as you know that the water remains boiling throughout the processing time, the product is safe.
Has any testing been done on electric pressure canners?
As of March 2024, no independent testing has been done. Presto has released a statement (https://www.gopresto.com/content/s/presto-precise-digital-pressure-canner) that their device was tested with the same method used to test food when developing new recipes. Professor Joy Waite-Cusic, head of Oregon State University’s food safety program, has reviewed the lab data given to her by Presto and found that in all trials except for spinach (for a currently unknown reason) the thermocouples recorded safe values in the jars of food. While Joy would like to organize independent testing to see if Presto’s results are duplicable, there are no current plans do to so. OSU’s current position is neither against or in support of using the Presto electric pressure canners as they are not able to independently verify safety. According to OSU, some independent testing was done on Carey electric canners, but these did not meet expectations.
Why don’t standard canners need to be tested?
Standard canners are tested every time a new recipe is developed. This is because testing is done on the jars of food, not the canner itself, to determine if the process has killed enough microbes. There is no need to test whether the device comes to a certain pressure, as that is easily observed by a dial or weighted gauge, and the end goal is destruction of microbes within jars of food.
At this time, r/canning will not allow reccomendations for electric pressure canners. We will continue to wait for testing to be performed by a group that will not profit from desirable results.
by MerMaddi666