Whole Sea Salt: composition, harvesting process, nutritional properties, applications, and sustainability

Definition
Whole sea salt (also known as unrefined sea salt) is obtained through the natural evaporation of seawater, using sun and wind, and is not chemically refined. It retains its natural balance of sodium chloride and trace minerals, unlike refined salt which is purified and may include additives such as anti-caking agents.

Whole sea salt is typically harvested from traditional salt flats or marine saltworks, and can vary in color, texture, and mineral content depending on the source.

1. Average composition (per 100 g)

• Sodium chloride (NaCl): 90–95%

• Magnesium (Mg²⁺): 0.1–0.5%

• Potassium (K⁺): 0.05–0.3%

• Calcium (Ca²⁺): 0.05–0.2%

• Iron, zinc, copper, manganese: trace amounts

• Sulfates, bicarbonates, iodides: variable

• Residual moisture: up to 5% (if not dried)

Exact values may vary depending on the geographic origin, drying method, and local seawater composition.

2. Harvesting process

1. Natural evaporation
   Seawater is channeled into shallow ponds (called salterns), where solar energy and wind gradually evaporate the water.

2. Crystallization
   As salinity increases, sodium chloride crystallizes first, followed by other minerals. The salt forms layers at the bottom of the ponds.

3. Manual or mechanical harvesting
   The salt is collected once crystallization is complete, typically without washing, to preserve its natural mineral content.

4. Air-drying or low-temperature drying
   To avoid mineral loss, drying is done naturally or at low temperatures, preserving the salt’s structure and trace elements.

3. Nutritional and functional properties

• Provides sodium, essential for nerve transmission, fluid balance, and muscle contraction

• Contains magnesium, calcium, and potassium, supporting cardiovascular and muscular function

• May include natural iodine, though not standardized

• No added chemicals or anti-caking agents, making it ideal for natural or clean-label diets

4. Comparison with refined table salt

5. Main uses

Culinary

• Used as a natural seasoning in both raw and cooked dishes

• Ideal for artisan breads, fermented vegetables, and traditional recipes

• Common in macrobiotic, organic, and paleo diets

Cosmetic and wellness

• Used in salt baths, exfoliating scrubs, and spa treatments

• Basis for thalassotherapy and mineralizing skin care

• Helps with skin hydration and circulation

Traditional food preservation

• Salt-curing of meats and fish

• Natural fermentation (e.g., sauerkraut, pickles, miso)

6. Safety and health considerations

• Safe in moderate amounts

• High sodium intake (from any source) may raise blood pressure in sensitive individuals

• Trace minerals are beneficial, but whole sea salt is not a reliable iodine source → not sufficient for populations at risk of iodine deficiency

• Unrefined salt may contain tiny amounts of organic residues or marine particles, generally harmless

7. Environmental and sustainability aspects

• Produced through solar evaporation, requiring no fossil fuel energy

• Minimal environmental impact if harvested responsibly

• Traditional salt flats (e.g., in France, Portugal, Italy) support coastal biodiversity, serving as habitats for migratory birds and halophytic plants

• Supports local economies and artisanal heritage

• No chemical inputs or industrial refining → aligns with sustainable production models

8. Conclusion

Whole sea salt is a natural, unprocessed mineral product that offers more than just sodium: it brings a subtle complexity of flavor and trace elements often removed in refined salt. Its low environmental impact, traditional harvesting methods, and clean composition make it highly appreciated in natural and holistic nutrition.

As with any salt, moderation is key, but choosing whole sea salt supports both culinary quality and sustainable sourcing practices.

Molecular Formula   CINa

Molecular Weight    58.44

CAS   7647-14-5

Sea salt studies

References____________________________________________________________________

(1) Khajedaluee M, Rajabian R, Seyyednozadi M. Education achievements and goiter size ten years after iodized salt consuming. Int J Prev Med. 2013 Aug;4(8):876-80.

Abstract. Background: Approximately 2.2 billion (2200 million) of the world population are living in the area with Iodine deficiency (ID), most of them in the developing countries. In IRAN about 2 million are exposed to Iodine deficiency. Most of the complications of ID are not curable, especially brain damage. On the other hand, adding iodine to daily salt is a suitable program for decreasing iodine deficiency. This has been the main aim of IDD National committee since 1986. This study is a before-after preventive trial, and was conducted to determine the effect of iodized salt in preventing the disorders of Iodine deficiency. Methods: This study was a preventive field trial in 2 stages before and after prevention. Since 1995, Iodized salt has been distributed in Tabas in Yazd province. Sample of 2,150 students aged 6-18 years were chosen by stratified cluster random sampling method from 24 schools, 12 schools from rural and 12 from urban areas. Goiter frequency and educational status were determined using WHO criteria and mean scored, respectively. Results: Prevalence of goiter has decreased from 34 to 25 percent after 10 years (P < 0.001). The prevalence in urban areas has decreased from 35.8 to 23.5 percent and in rural from 35.6 to 28.5 percent (P = 0.02). Prevalence of Goiter has changed from 32.8 to 20 percent and from 39.5 to 31.5 in boys and girls, respectively (P < 0.001). There was a statistically significant relation between educational status and goiter frequency before and after prevention (P = 0.01). There was also a statistically significant relation between educational status in 2 stages, before and after intervention (P < 0.001). Conclusions: ALTHOUGH, THERE ARE SOME CONFOUNDING VARIABLES, SUCH AS: educational resources development, improved educational methods, and enhanced family emphasis on extracurricular education, increased frequency of students in higher education after intervention shows the iodine effects on mental function.

(2) Laurberg P, Jørgensen T, Perrild H, Ovesen L, Knudsen N, Pedersen IB, Rasmussen LB, Carlé A, Vejbjerg P. The Danish investigation on iodine intake and thyroid disease, DanThyr: status and perspectives. Eur J Endocrinol. 2006 Aug;155(2):219-28. doi: 10.1530/eje.1.02210. Erratum in: Eur J Endocrinol. 2006 Oct;155(4):643. 

Abstract. Objective: Denmark was an area of iodine deficiency, and mandatory iodine fortification of table salt and salt in bread (13 p.p.m. iodine) was initiated in 2000/2001. The Danish investigation on iodine intake and thyroid disease (DanThyr) is the monitoring of the iodine fortification program. Design and methods: DanThyr consists of three main parts: a study of population cohorts initialized before (n=4649) and after (n=3570) iodization of salt, a prospective identification of incident cases of overt hyper- and hypothyroidism in a population of around 550,000 people since 1997, and compilation of data from the national registers on the use of thyroid medication, thyroid surgery, and radioiodine therapy. Studies were carried-out in parallel in subcohorts living in areas with differences in iodine content of ground water. Results: The study showed profound effects of even small differences in iodine intake level on the prevalence of goiter, nodules, and thyroid dysfunction. Mild and moderate iodine deficiency was associated with a decrease in serum TSH with age. Other environmental factors were also important for goiter development (increase in risk, smoking and pregnancy; decrease in risk, oral contraception and alcohol consumption), and the individual risk depended on the genetic background. Environmental factors had only a minor influence on the prevalence of thyroid autoantibodies in the population. There were more cases of overt hypothyroidism in mild than in moderate iodine deficiency caused by a 53% higher incidence of spontaneous (presumably autoimmune) hypothyroidism. On the other hand, there were 49% more cases of overt hyperthyroidism in the area with moderate iodine deficiency. The cautious iodine fortification program, aiming at an average increase in iodine intake of 50 mug/day has been associated with a 50% increase in incidence of hyperthyroidism in the area with the most severe iodine deficiency. The incidence is expected to decrease in the future, but there may be more cases of Graves' hyperthyroidism in young people. Conclusion: A number of environmental factors influence the epidemiology of thyroid disorders, and even relatively small abnormalities and differences in the level of iodine intake of a population have profound effects on the occurrence of thyroid abnormalities. Monitoring and adjustment of iodine intake in the population is an important part of preventive medicine.