Several people have asked me about atmospheric steam canning. It is growing in popularity so let’s explore the uses, advantages, and disadvantages of this method of food preservation. In 2015 atmospheric steam canning was approved by the National Centre for Home Food Preservation and the USDA as a safe and efficient alternative to water-bath canning.
The steam canner (pictured here) uses a small amount of water (usually about 2 to 3 litres) or a couple of inches that creates an enclosed environment of steam at a temperature of 212 F or the same as boiling point. Jars are placed on a rack above the boiling water and are processed by the hot steam instead of water. This approach saves on water, eliminates heavy lifting associated with water-bath canners, saves on electricity or propane and saves time.
The advantages of steam canning are clear, but there are a couple of disadvantages to consider. Steam canning should not be used if processing times exceed 45 minutes because the water can run dry. Also, most steam canners are made of aluminum which cannot be used on induction burners. However, Vittorio does produce a stainless-steel version which addresses this problem.
As an alternate to water-bath canning, steam canning is suitable for processing high acid foods. As always, it’s important to use modern, tested recipes from reputable sources to ensure proper acidity levels. Processing times are the same for steam canning as they are for water-bath canning, adjusting times for altitude.
With the steam canner, you can warm your jars on the rack inside the canner with the stove on a low heat until you have filled the jars leaving a headspace as directed in the recipe. Once the filled jars are on the rack and the lid is on, increase the heat to boil the water. Once the steam is being release from the tiny port in the lid in a continuous stream of about 6 inches in length, begin your processing time. Once the processing is done, turn off the heat and allow the pot to rest for at least 3 minutes before carefully removing the lid of the canner. Remove the jars and allow them to stand undisturbed for 24 hours.
Steam canners are available on Amazon and at Peavey stores (formerly TSC). If you happen to have a Ball electric water bath canner, it can also be used for steam canning. Add water to the pot just below the lower ridge (about 2 inches of water), then rest the diffuser on the ridge. This becomes the rack for the jars. Proceed as described above.
Atmospheric steam canning is becoming increasingly popular for very good reason. The canners are inexpensive, use less water, are lighter, save time and energy and are as effective as water-bath canners for safe processing of foods. So, consider adding this method to your home food preservation repertoire.