When a recipe calls for “sour salt” it is referring to citric acid. It’s a white granulated powder that is extracted from the juice of citrus and other acidic fruits (gooseberries, lemons, limes and pineapples). It can also be created by fermenting glucose with special citric acid producing bacteria.
The strong, tart taste of citric acid is used as a flavoring agent to foods, beverages and even a couple of our salt-free blends. Careful not to use too much as it can overpower a dish. If you’re making traditional borscht, this is the key ingredient to impart that tart flavor.