How does salt-curing preserve fish?

Salt-curing preserves fish primarily by reducing water activity, which is a fundamental requirement for bacterial growth and spoilage. By adding salt, the moisture content within the fish flesh is significantly lowered, creating an environment that inhibits the proliferation of most microorganisms.12

There are two primary methods used in the industry:

• Dry Salting: Butchered fish are buried in salt, allowing brine to drain away. This process reduces the water content from a fresh level of 75–80 percent to approximately 50 percent, while increasing the salt concentration to about 25 percent. In heavy or hard-cure salting, warm air is further applied to reduce water content to 20 percent and increase salt levels to 30 percent.1
• Pickle-curing: Fish are preserved in airtight barrels using a strong pickling solution created by dissolving salt in the fish's own body fluids.1

While salt acts as an effective preservative, it is important to note that certain salt-tolerant bacteria, known as halophiles, can still thrive in high-salt environments and may occasionally be found on salted fish.2