How Salt Preserves Food

Before refrigeration became common, salt was a popular food preservative. It is still used in many products, including bacon, ham, pickles, and jerky, but modern versions of these foods actually contain much less salt than the level needed to prevent microbial growth. Seawater tastes salty, yet it is only about 3.5% salt. A 10% salt concentration is needed to prevent bacterial growth and 20% salinity is required to actually kill bacteria and molds. Yet, salt does work as a preservative.