You must have rarely observed it in your life. Most of the salt we buy only indicates the date of production on the package, and there is no shelf life, which makes us feel that the shelf life of salt is permanent and will not deteriorate no matter how long it is kept. But this is not the case, and the shelf life of salt also exists.

Shelf life of salt

Salt has a "shelf life", but packaging bags can be free of shelf life. According to Article 9 of the Measures for the Administration of Food Labeling promulgated by the General Administration of Quality Supervision, Inspection and Quarantine on July 24, 2007 and implemented on September/KLOC-0, 2008, edible salt, vinegar and solid sugar will not deteriorate under normal circumstances, and the shelf life of food can be exempted. The main component of salt is sodium chloride, which is stable. Moreover, solid salt itself will create a high osmotic pressure environment and inhibit the growth and reproduction of ordinary microorganisms. Therefore, some salt packages on the market have no shelf life, only the date of production. Why can't microorganisms grow in hypertonic environment? Microorganisms need water as much as humans for survival and reproduction. In a very salty or sweet environment, the moisture in microorganisms will be sucked out, which will lead to the death of microorganisms.

From the perspective of food practitioners, "shelf life" is the best edible date or shelf life. Edible salt will become damp even if it is preserved for a long time after being unpacked, and it will fall into foreign objects and affect eating if it is not preserved properly. In addition, functional salts such as iodized salt, zinc salt and iron salt have a shelf life because they are related to the existing forms of these trace elements and the way of salt preservation.

So how long is the shelf life of salt? Generally, the shelf life of refined iodized salt is 5 years, and that of low sodium salt is 3 years. Nutrients such as calcium, iron, zinc and selenium will be marked with the corresponding shelf life. For example, the shelf life of iron salt is 1 year; Selenide has a shelf life of 8 years; The shelf life of adding calcium salt is 8 years; The shelf life of adding zinc salt is 8 years.

Although the shelf life of salt is long after all, and there is no need to mark it on the package, it is best to eat it within 1 year after opening.