When you’re cleaning out your spice cabinet and you come across a dusty container of salt that was hiding behind everything else for who knows how long, your first impulse may be to throw it out. Your second impulse may be to keep it. After all, salt can’t go bad…or can it? But maybe it could have lost its flavor over time? Gotten stale? Is there a point at which you should throw out your salt?
Can Salt Go Bad?
As it turns out, the answer is no…and yes. Natural salt without additives won’t ever go bad. Why? For food to spoil, fungal, bacterial, yeast or other microbial growth has to take place. All of these require water. Salt doesn’t contain water, so it doesn’t support microbial growth, meaning it won’t spoil. Remember, salt is a preservative and it’s been part of the oceans’ waters or sitting in rocks for millions of years prior to being harvested, so another year or two in your pantry really isn’t going to be detrimental.
But what about the “yes” portion of the answer? If you’ll notice, we said above that natural salt without additives won’t go bad. Refined table salt–the pure white stuff you probably grew up using–will go bad. It’s not because of the salt, though. It’s because of the additives. Iodine and anti-caking agents degrade over time, reducing the shelf life of the salt to about five years.
(Sidebar: a couple of types of sea salt, such as Celtic and fleur de sel, do contain small amounts of water. We suggest using these within the manufacturer’s recommended timeframe.)
Why Does Salt Have an Expiration Date?
If your salt has an expiration date, it’s either refined salt with additives or that’s a “best by” date slapped on there by the company for reasons not at all related to when the salt will be best. (Some online retailers won’t carry food products unless they have a “best by” date, even if said product is impervious to spoilage.) As long as your salt is natural additive-free salt, it’s safe to consume it regardless of the date on the label, provided no contamination has occurred.
Okay, But Will Salt Lose its Flavor Over Time?
Alright, so old salt will be safe to eat, but will it taste like salt? Doesn’t it lose its flavor?
The salt we eat is the compound sodium chloride, or NaCl. This compound is incredibly stable and won’t degrade and lose flavor over time. Unlike most spices, salt isn’t derived from a plant, so there’s no freshness factor.
The notion of salt losing flavor originated from a verse in the Christian bible that mentions salt losing its savor, which was strictly a metaphor in a religious lesson and not advice on seasonings.
Interestingly, though, salt back in New Testament times often did lose its “savor.” In those days, salt was generally not pure. It contained multiple other compounds, most of which held up to humidity better than sodium chloride. So, if the salt was exposed to the typical humidity of a place like Israel, the sodium chloride would eventually evaporate while the other compounds wouldn’t, leaving behind a white substance that appeared to be salt but had none of its flavor.
How to Store Salt
Natural additive-free salt won’t go bad or lose flavor, but that doesn’t mean it’s immune to its environment. Storing it properly is key to keeping it well. Salt is hygroscopic, meaning it attracts and holds water molecules from the surrounding environment. In humidity, it will clump. In a kitchen where you’re cooking a lot, it will absorb steam and odors, which can affect its taste. To prevent this, store your extra salt in an airtight container or pouch. A grinder or salt shaker is fine for small amounts of salt because not much air can get in and you’re likely actively using it. If you’re putting salt out in a bowl, make sure you’re using it within a few days or covering it with a lid of some sort to keep it from tasting like whatever you made for dinner last night.