Is it OK to use a salt substitute in a brine?
Salt substitutes fall into two categories: salt-free brands that replace all of the sodium chloride with potassium chloride, and low-salt brands that are a combination of the two minerals. We recently sampled both types in various cooking applications and found some sodium to be necessary to buffer the bitterness of the potassium chloride. To test whether a low-salt brand would be effective in a brine, we cut up two whole chickens and soaked one in a standard saltwater solution and the other in a brine made with our taste-test winner, LoSalt, which is made up of two-thirds potassium chloride and one-third sodium chloride. We pan-roasted the chickens and made a quick sauce with the drippings.
The results surprised us. While we expected to dislike the flavor of the chicken brined in the salt substitute, only a few tasters detected minor bitter notes—and most considered the flavor completely acceptable. Even more surprising was the finding that both samples were equally moist and juicy. When we did some further investigation, we learned that while the positive sodium ions in table salt are responsible for adding flavor, it’s the negative chloride ions that bind to the proteins and cause them to swell and absorb moisture. Potassium chloride provides the same negative ions as table salt, and thus has a nearly identical effect when used in a brine.
The bottom line: It’s fine to brine with a salt substitute. Just be sure to use a low-salt (not a salt-free) brand.