Q: I have been told that its fine to use sterilized jars and put HOT soup in them — then turn them upside down and let them seal themselves.
Is this a good method for low risk foods?
— Question asked by Tara
Marisa: Tara, whoever told you that that was an appropriate way to can hot soup greatly misled you. Soup is a low-acid food, which means that it's a fabulous environment for botulism to grow. While you will achieve a seal with the upside down method, it won't be a strong one and there's a enormous chance of contamination and spoilage. So please, do not attempt to put up soups in this manner (and if you've already done so, in the interest of safety, I would recommend throwing them out immediately).
The ONLY way to preserve soups and stocks is to pressure can them or freeze them.
Marisa McClellan, our guest expert this week, is answering your questions on canning and preserving. Marisa writes Food In Jars, a blog devoted to canning, preserving, and other food in jars. She also teaches canning workshops.
Marisa couldn't get to all of your questions this week, but she's going to answer a few more of your questions over at her blog this weekend. So make sure to check in there and see if your canning question was answered!
Previous questions about canning answered by Marisa: