How is Sea Salt Purified?
Sea salt purification involves a multi-step process to remove impurities and achieve a high level of sodium chloride purity. The exact methods vary depending on the desired purity level and scale of production, but common techniques include:
One common method involves a rinsing process. The harvested sea salt is first rinsed in a brine solution to remove calcium and other impurities. Subsequently, it's rinsed in bay water to dissolve magnesium chloride. This leaves behind nearly 99.8% pure sodium chloride. [Source: The Kitchn, 2019]
Dissolution, Filtration, and Crystallization
Another widely used approach involves dissolving the raw sea salt in water. This solution is then filtered to remove insoluble impurities such as sand and organic matter. The purified brine is then evaporated, allowing the sodium chloride crystals to reform, leaving behind other dissolved salts and minerals. [Source: Reddit r/chemistry, 2023]
Additional Purification Methods
While the above methods are common, further refinement may be employed for specific applications. This might involve techniques like:
- High-heat baking: This can remove additional impurities and potentially improve crystal structure. [Source: Reddit r/chemistry, 2023]
- Recrystallization: Dissolving and recrystallizing from purified water multiple times can greatly increase purity levels. [Source: Quora, 2021]
- Distillation and reverse osmosis: These methods are used primarily for desalination of seawater before salt production, not typically as a direct purification method for harvested salt. [Source: Quora, 2021]
Several commercial producers, such as Cargill, offer purified sea salt. Their products are described as food-grade, granular, white crystalline sodium chloride, produced under stringent process controls and harvested from the Pacific Ocean. They use evaporation of brine to obtain the salt crystals. [Source: Cargill, various sources]
The purification method used depends heavily on the intended use and the desired level of purity. For example, kosher sea salt might only undergo basic purification to maintain a coarse grain and natural mineral content, while industrial-grade salt needs a more intensive approach.
