Salt's Sanitizing Power: Understanding the Osmosis Effect

Salt sanitizes by drawing water out of bacteria and other microorganisms through osmosis. Osmosis is the movement of water molecules from an area of lower solute concentration to an area of higher solute concentration. When salt is added to water, it creates a higher solute concentration outside of the bacteria cell than inside the cell. This causes water to move out of the cell and into the water, causing the cell to dehydrate and die.

Salt can also disrupt the cell membranes of bacteria. Cell membranes are made up of phospholipids, which are molecules that have a hydrophilic (water-loving) head and a hydrophobic (water-hating) tail. When salt is added to water, it can interact with the hydrophilic heads of the phospholipids and cause them to become disoriented. This can disrupt the structure of the cell membrane and cause the cell to leak its contents and die.

In addition to these two mechanisms, salt can also inhibit the growth of bacteria by preventing them from producing the enzymes they need to survive.