Why Does Salt Have an Expiration Date? – Lifehacker
Photo: Claire Lower
Salt is an incredibly common ingredient that most of us take for granted. It’s a simple, inorganic (meaning “not carbon based”) molecule comprised of two tiny ions, sodium and chloride, but its ability to flavor and preserve is what makes it valuable—so valuable that it made its way into the word “salary.”
Salt preserves food by drawing out moisture, suppressing the growth of harmful bacteria, and encouraging the growth of helpful bacteria—so why do canisters of the stuff come with expiration dates?
The culprit is not sodium chloride, but the additives some manufacturers mix in with it to prevent clumping, or add nutrients. Iodine, anti-clumping agents, and trace minerals in pink, red, or black salts can degrade with time, but degradation doesn’t guarantee harm. T...