Black salt, also known as Kala Namak, should ideally be stored in airtight glass or ceramic jars to protect it from moisture and strong odors, which can affect its flavor and quality.
Black salt is hygroscopic, meaning it readily absorbs moisture from the air. This can cause it to clump together and lose its characteristic pungent aroma. Glass and ceramic jars are non-porous materials that provide an excellent barrier against moisture. They also prevent the salt from absorbing odors from the surrounding environment. Plastic containers, on the other hand, can sometimes impart a plastic taste or smell to the salt, and they are not as effective at preventing moisture absorption. Therefore, opting for glass or ceramic is the best way to maintain the quality and flavor of your black salt over time. Make sure the jar has a tight-fitting lid to further minimize exposure to air and humidity.
If you live in a particularly humid climate, consider adding a small silica gel packet to the jar to absorb any excess moisture and further extend the shelf life of your black salt.