Q: For canning, my grandmother used a big pot with a lid. Can I can this way, too?
A: Yes - but only for some foods. The original home canning process was just a big pot with a well fitted lid - essentially what we now call a hot water bath canner or a boiling water canner. (I talk about this in my post on preparing to can.) However, modern science has found some foods canned in this way could host botulism. Yes, the incidence of botulism is generally low in this country, but nobody wants to be that sick. Botulism can even cause death, especially among the young and old. So vegetables, meats, poultry, and fish should be canned with a pressure canner, which can reach higher temperatures, thereby killing off any harmful germs. Hot water bath canners are perfectly fine for canning tomatoes and other fruits, pickles, and jams and jellies. Go ahead and use a big pot with a lid if you want, but do fashion some sort of canning rack for the jars.
Q: Can I can anything? I have a great recipe for salsa that I'd like to can.
A: It's not considered safe to can recipes not recently and scientifically tested as safe for home canning. Again, it's all about the risk of botulism and food poisioning. To be considered safe, the recipe must be tested for acid levels and a safe cooking time must be determined. When I first started canning, I was disappointed to learn this. However, now I realize that canning is a superb way to preserve many basics (like tomatoes for adding to cooking recipes), And while the approved recipes for things like stew aren't all that thrilling, I still can them because when we're ready to eat said stew, I can make it delicious by adding a few simple ingredients (like herbs).
Q: Can I tweak recipes just a little bit? You know, add some herbs or lower the quantity of a certain ingredient?
A: This is not considered safe, since it can alter the amount of acidity in the recipe. Add herbs and extra ingredients later, just before you eat the food.
Q: Do I have to use canning jars? My grandma used glass mayo jars for canning.
A: The official answer is that you should only use actual canning jars for canning, but my mother-in-law uses mayo jars in her hot water bath canner. However, this type of jar might break - resulting in possible injury and a complete loss of the food in the jar. In addition, never use non-canning jars in a pressure canner because they are far more likely to break.
Q: One of the reasons I'm interested in canning is I'm concerned about BPA in commercial canned foods. Then I heard canning jar lids have BPA in them. Is this true?
A: Although the Federal Drug Administration (FDA) says BPA (Bisphenol A) isn’t harmful to humans at the levels found in food products, animal tests link BPA to problems such as poor brain development and certain cancers. Although the media mostly focuses on BPA in baby and water bottles, it's true home canning lids contain small amounts of BPA. The good news is this: The BPA in home canning products is sealed between the two layers of metal that make up the lids. (UPDATE 6/9/13: Since the fall of 2012, Ball has been selling BPA free canning lids; this spring, you'll find all new boxes of lids are marked "BPA Free.")
This isn't enough reassurance for some, which has brought about two different products. One is European style canning jars (sometimes called “hermetic” canning jars) with rubber gaskets and lids attached to the jar with steel clips. The USDA recommends against these jars for safety reasons but, some canners argue, they’ve been in use for nearly 100 years overseas. Such jars should be purchased from specialty canning stores (often found online), since not all hermetic jars are suitable for home canning. Antique jars should not be used because their gaskets may not seal properly. Another way to get around the BPA in canning lids is to use reusable lids, which are much like the rubber lids our grandmothers used.