The internet can be a wealth of helpful information but when it comes to home canning, be cautious of suggestions for canning food in non-traditional ways.
The USDA still recommends that all high-acid foods (pickles, jams and jellies, fruits, salsas and tomatoes) should be processed in a water-bath canner or pressure canner and all low-acid foods (vegetables and meats) in a pressure canner. Any other methods could put you and your family’s health at risk. Here are a few unsafe canning methods and the reasons why they are not considered safe:
Oven canning: Oven canning was a popular method of home canning around the turn of the 20th century, in part because it did not result in a sweltering kitchen and removed the risk of steam burns, but has since been deemed an unsafe method of canning.
Oven canning is dangerous because the temperature will vary according to the accuracy of oven regulators and circulation of heat. Dry heat is very slow in penetrating into jars of food. Also, jars explode easily in the oven.
Open kettle: Open kettle canning has been considered an unsafe home canning practice since the 1980s due to the high risk of contamination during processing. Open kettle canning presents a serious health risk because the temperatures reached using this method are not high enough to destroy all harmful organisms that may be in food.
Dishwasher canning: There is no way to control the temperature or processing time in a dishwasher. Even at its hottest setting the temperature of the water during the cleaning and rinsing cycle is way below the temperature needed to kill harmful bacteria.
Electric multi-cooker/canner: Even if there are instructions for pressure canning in the manufacturer’s directions, these appliance DO NOT meet the standards for safe home pressure canning. It will only hold up to four pint jars, and the National Center for Home Food Preservation’s guidelines are that a pressure canner MUST be able to hold four quart jars in order to have the volume necessary to process low-acid foods.
The heat-up and cool-down time would be much less in a smaller appliance (than a traditional pressure canner), making the entire processing time in this appliance LESS than is needed for low-acid home canning processing times.
Microwave canning: Microwaved food may reach a boiling temperature, but heating is not even throughout the jar. In order to kill bacteria and spores such as botulism, low-acid foods must reach an internal temperature of 240 degrees F, which can only be reached through the use of a pressure canner.
There also is a danger that jars may explode within the microwave or as the food is being removed from the oven.
If you don’t have a pressure canner or boiling water bath canner, freezing is always a safe option.
Here is an easy recipe for refrigerator jam:
Easy Strawberry Jam from Fresh Strawberries
- 1-3/4 cups crushed strawberries (about 1 quart)
- 4 cups sugar
- 2 tablespoons lemon juice
- 1 pouch liquid pectin
Measure 1-3/4 cups crushed strawberries. Place in an extra large bowl. Add sugar, mix well and let stand for 10 minutes.
Measure lemon juice into a small bowl. Add liquid pectin and stir well. Stir the pectin/lemon juice mixture into fruit and continue stirring for 3 minutes. Pour jam into clean, dry freezer containers or half-pint canning jars, leaving 1/2-inch headspace.
Cover container. Let stand at room temperature until set (up to 24 hours). Freeze or refrigerate.
Makes about 4 half-pint jars.