Kosher sea salt and table salt are both ways of seasoning our foods. However, their shelf life is very different. Sea salt has a longer shelf life of about three years while table salt tends to diminish after a year. While both kind of salt are good when used in cooking, there is a key difference between them. Sea salt has been proven to improve with age as it retains its fine mineral properties. This makes it preferable to table salt for anyone who wants to enjoy the healthy benefits of minerals over time.
Table salt, on the other hand, lacks the mineral properties that sea salt acquires with time. Table salt tends to lose its color, its texture becomes coarse and it develops a musty or stale flavor. This is because table salt contains more sodium than kosher salt. Table salt has a tendency to come into contact with moisture and bacteria more frequently which affects its shelf life. The larger crystals do not lend themselves easily to regular salt shakers, which explains why it often gets stored in plastic bags in the fridge. Also, in humid climates, open storage such as this may eventually result in mineral clumping (which is also found in sea salts) which may make it less desirable to consumers.
The molecular structure of kosher salt makes it slightly less salty than sea salt. Unlike sea salt, kosher salt does not have a single crystal structure and the salt contains six molecules instead of the typical four. This makes kosher salt less dense than sea salt, so some of it tends to dissolve away more easily. As a result, it has a less salty taste. It also has a lower salt concentration that most sea salts have. The general trend in the industry is to minimize salt content by one percent or less.
Most sea salts retain a cloudy appearance due to its composition. Soluble particles in the salt absorb water and get stuck on the surface which forms clouds as the water evaporates. As these cloud particles settle, they mix with airborne molecules floating in the air thus forming clouds of salty flavor. These particles are usually larger and darker than un-saltized sea salts so they retain less of their original flavor. This is why some sea salts taste better after being washed while others retain their salty flavor when they are left on the table.
One of the differences between kosher sea salt and table salt is that its production is more regulated. Mined salts are harvested by dredging out an area of the sea floor and then collecting the salt from the sediment. In this process, more minerals are removed compared to the production of table salt. Because it is easier to regulate production levels, kosher sea salt has a higher concentration of vital minerals such as calcium and magnesium.
Despite the large amount of pollutants removed during the harvesting process for kosher salt, it still does not contain the heavy metals found in regular table salt. The only metal found in kosher salt is lead which is treated so that it is less damaging to the environment. This is done by forming a compound with lead chloride that helps to reduce the amount of acid produced during sea salt harvesting. Because of the regulations required to be met by kosher salt producers, the color and taste of this salt is often highly prized among consumers.