Salt Questions · Cooking & kitchen

Why does salt preserve meat from spoiling?

By The Salt AlmanacUpdated November 8, 20262 sources cited

Water activity

Microbes need available water. Scientists measure it as water activity (a_w), from 1.0 for pure water down to 0 for completely dry food. Fresh meat is about 0.99. Salt binds water, lowering the a_w:

• Most spoilage bacteria stop growing below about 0.91.
• Some salt-tolerant bacteria, such as Staphylococcus aureus, can grow down to about 0.86.
• Most moulds stop around 0.80, though some go lower.

Salt as part of a system

Traditional curing combined salt with drying, smoking, cold and sometimes nitrates. Salt alone at modest levels doesn't make meat safe at room temperature. Modern curing follows tested recipes and measured curing salts.

Related on The Salt Almanac

More cooking & kitchen questions

• How do you remove excess salt from roasted vegetables?
• Is flaky sea salt the same as coarse sea salt?
• What is the difference between kosher salt and sea salt?
• Can I use table salt instead of kosher salt in baking?
• How much salt do I add per pound of ground beef?
• Why do recipes say to use unsalted butter and add salt later?

See all 100 salt questions