Ask the Goats is a weekly series in which we attempt to answer your questions about growing, making, eating, and preserving food. Got a question for the goats? Drop us a line at email@example.com.
Q. Hi. I am not new to canning. But something happened this year that has never happened before. I canned 16 quarts of vegetable soup. I used the water bath method and processed them for 1 hour. I checked the seals and they were good. One week later the lids started pinging. What went wrong? That was an awful lot of work to throw away. I am very disgusted. P.S. My salsa, peach preserves, strawberry jam are all sealed and delicious.—Mary
A. Alas, Mary, vegetable broth is a low-acid food, and therefore not safe for water-bath canning. For the purposes of canning, all foods are either high-acid or low-acid foods. The kinds of food-born pathogens that can live in a high-acid environment can be killed fairly easily with moderate heat, so you can process them in a boiling water bath. Low-acid foods, on the other hand, can harbor botulism spores that are not destroyed at 212°F. Low-acid foods must be processed in a steam pressure canner that can reach much higher temperatures (usually 240ºF).
Remember, only fruits (excluding tomatoes, figs, green mangoes, and white peaches) and certain kinds of fermented pickles are acidic enough for water-bath canning without adding acid. For everything else, you have to either acid—sometimes in substantial quantities—or use a pressure canner.
Pressure can vegetable stock just as you would chicken stock (for step-by-step directions, click here). The Ball Blue Book recommends 35 minutes for quarts at 10 pounds pressure. If you don’t have a pressure canner, you’ve got to freeze it.
In happier news, the winner of the Put ‘Em Up! giveaway is Amanda Nelson, who’s new to canning and expecting twins! I think your strategy to put up as many nibble-ables as possible is an excellent strategy.