I’d never heard of Pickle Crisp until a couple of weeks ago, when I was giving a radio interview and a caller mentioned the product. Pickle Crisp, I learned, is a trade name for calcium chloride, a common additive in commercial canning. Calcium chloride is used for several purposes, but in pickles it is mainly a firming agent.
On searching the Web for more information, I learned that Pickle Crisp had been marketed by Jarden, the company that makes Ball jars, but was no longer available.
To find out more, I contacted Lauren Devine at Jarden. The company sold Pickle Crisp for about two years. It was intended to replace pickling lime, which home picklers, particularly in the South, have long used to firm such pickles as bread-and-butters and pickled figs. But lime is troublesome to use: You must first soak the fruit or vegetable pieces in a mixture of lime and water, and then rinse and soak them repeatedly until the water is clear and the lime won’t affect the pickle’s pH much. Calcium chloride is easier to use: You add 1/8 teaspoon along with the fruit or vegetable pieces and the pickling liquid to a pint jar, or 1/4 teaspoon to a quart jar. (Jarden has tested Pickle Crisp only with fresh pickles, not with fermented ones.)
Unfortunately for Jarden, sales of Pickle Crisp were slow, and only upon removing the product from the market did Jarden realize that there was much demand for it. Jarden decided to bring the product back, but in improved form. The old Pickle Crisp was a powder that tended to dissolve into steam. The new version will have bigger grains.
The new Pickle Crisp should be in the home-canning sections of supermarkets and farm-supply stores next March or April.
UPDATE 2022: Today Pickle Crisp is widely available in stores. Its firming effect is subtle, unlike that of lime. Some people object to the strong, sour taste of calcium chloride. See also “Testing Pickle Crisp.”