It can be found in treasure chests throughout the game, and can drop from enemies.
Salt Bug Farming
Salt bugs are an enemy type which flies away whenever the player gets to close or hits it. They can be held in place by Sam's energy bubble and each time it's stuck it will drop some Salt. Players can enter/exit maps to respawn salt bugs, effectively allowing them to farm salt as their energy recharges.
Salt Bug Achievement
There's an achievement specifically awarded from collecting Salt from Salt Bugs. It requires the player collect (cumulatively) 1,000 Salt from them.
|Salty Stinking Rich||Obtain 1,000 salt from off a Salt Bug.|