Sea salt: Difference between revisions

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{{Short description|Salt produced from the evaporation of seawater}}

'''Sea salt''' is the salt found in certain bodies of water, notably [[oceans]] and [[seas]], and certain [[river]]s. It is the key differentiation between "saltwater" and "freshwater".

{{Use dmy dates|date=February 2019}}

[[File:Salt Farmers - Pak Thale-edit1.jpg|thumb|Sea salt harvesting in Pak Thale, [[Phetchaburi province|Phetchaburi]], Thailand]]

[[File:Marakkanam Salt Pans.JPG|thumb|A [[salt evaporation pond]] in [[Tamil Nadu]], India]]

'''Sea salt''' is [[salt]] that is produced by the evaporation of [[seawater]]. It is used as a seasoning in foods, [[cooking]], [[cosmetics]] and for preserving food. It is also called '''bay salt''',<ref>{{cite book | url= https://archive.org/details/bub_gb_H6wAAAAAMAAJ | last= Brownrigg | first= William | year= 1748 | title= The Art of Making Common Salt, as Now Practised in Most Parts of the World | publisher= C. Davis | pages=[https://archive.org/details/bub_gb_H6wAAAAAMAAJ/page/n43 12] <!--access-date=November 2007-->}}</ref> '''solar salt''',<ref name="FORBES1955">{{cite book|last=Forbes|first=R. J.|title=Studies in Ancient Technology|url=https://books.google.com/books?id=5JAeAAAAIAAJ&pg=PA169|access-date=10 December 2012|volume=iii|year=1955|publisher=Brill Archive|page=169}}</ref> or simply '''salt'''. Like mined [[rock salt]], production of sea salt has been dated to [[prehistory|prehistoric times]].

==Composition==

Scientific theories behind the origins of sea salt started with [[Sir Edmond Halley]] in [[1715]], who proposed that salt and other [[mineral]]s were carried into the sea by rivers, leached out of the ground by [[rain]] runoff. Seawater through the process of [[evaporation]] creates clouds which replenished rivers and streams with rain: the salt is not capable of evaporation, leaving oceans with a high level of salinity. Halley noted that of the small number of lakes in the world without ocean outlets, such as the [[Dead Sea]] and the [[Caspian Sea]], have very high salinity levels. Halley called this process "continental weathering".

[[File:Grano de sal marina, 2020-06-12, DD 01-16 FS.jpg|thumb|High-resolution image of a grain of sea salt]]

Commercially available sea salts on the market today vary widely in their chemical composition. Although the principal component is [[sodium chloride]], the remaining portion can range from less than 0.2 to 22% of other salts. These are mostly calcium, potassium, and magnesium salts of chloride and sulfate with substantially lesser amounts of many trace elements found in natural seawater. Though the composition of commercially available salt may vary, the ionic composition of natural saltwater is relatively constant.<ref name=":0">{{Cite web|url=https://www.lenntech.com/composition-seawater.htm|title=Major ion composition of seawater - Lenntech|website=www.lenntech.com|access-date=2019-03-14}}</ref>

{| class="wikitable"

|+

!Concentration of ion in sea water<ref name=":0" />

!mg/l

|-

|[[Chloride]]

|18,980

|-

|[[Sodium ion|Sodium]]

|10,556

|-

|[[Sulfate]]

|2,649

|-

|[[Magnesium]]

|1,262

|-

|[[Calcium]]

|400

|-

|[[Potassium]]

|380

|-

|[[Bicarbonate]]

|140

|-

|[[Bromide]]

|65

|-

|[[Borate]]

|26

|-

|[[Strontium]]

|13

|-

|[[Fluoride]]

|1

|-

|[[Silicate]]

|1

|-

|[[Iodide]]

|<1

|-

|'''Total dissolved solids (TDS)'''

|'''34,483'''

|}

==Historical production==

Halley's theory is partly correct: in addition, [[sodium]] was leached out of the ocean floor when the oceans were first formed. The presence of the other element of salt, [[chlorine]] results from "outgassing" of chlorine and other gases from the earth's core via volcanoes and undersea vents. The sodium and chlorine subsequently combined to form sea salt.

[[File:Sea salt, evaporation pond Walvis Bay (2014).jpg|thumb|left|Sea [[salt evaporation pond]] at [[Walvis Bay]]. [[Halophile]] organisms giving a red colour.]]{{See also|History of salt}}

Sea salt is mentioned in the [[Vinaya Pitaka]], a Buddhist scripture compiled in the mid-5th century BC.<ref name="Prakash2005">{{cite book|last=Prakash|first=Om|title=Cultural History of India|url=https://books.google.com/books?id=nzpYb5UOeiwC&pg=PA479|access-date=10 December 2012|date=1 January 2005|publisher=New Age International|isbn=9788122415872|page=479}}</ref> The principle of production is evaporation of the water from the sea [[brine]]. In warm and dry climates this may be accomplished entirely by using solar energy, but in other climates fuel sources have been used. Modern sea salt production is almost entirely found in [[Mediterranean climate|Mediterranean]] and other warm, dry climates.<ref>{{Cite web |title=¿Cómo es el proceso de la elaboración de sal? |url=https://www.foodunfolded.com/es/articulo/como-es-el-proceso-de-la-elaboracion-de-sal |access-date=2022-05-01 |website=www.foodunfolded.com |language=es}}</ref>

[[Image:FleurDeSel.JPG|thumb|"[[Fleur de sel]]" sea salt, Île de Ré]]

Such places are today called salt works, instead of the older English word [[saltern]]. An ancient or medieval saltern was established where there was:

# Access to a market for the salt<ref name="Murphy2009"/>

# A gently shelving coast, protected from exposure to the open sea

# An inexpensive and easily worked fuel supply, or preferably the sun

# Another trade, such as [[pastoral farming]] or [[Tanning (leather)|tanning]]—which benefited from proximity to the saltern (by producing leather, salted meat, etc.) and provided the saltern with a local market

In this way, [[salt marsh]], [[pasture]] (salting), and salt works (saltern) enhanced each other economically. This was the pattern during the [[Roman Empire|Roman]] and medieval periods around [[The Wash]], in eastern England.<ref name="Murphy2009">{{cite book|last=Murphy|first=Peter|title=The English Coast: A History and a Prospect|url=https://books.google.com/books?id=DeW9hRZ_yPUC&pg=PA37|access-date=10 December 2012|date=6 October 2009|publisher=Continuum International Publishing Group|isbn=9781847251435|pages=37–38}}</ref> There, the [[tide]] brought the brine, the extensive saltings provided the pasture, the [[fen]]s and [[Bog|moors]] provided the [[peat]] fuel, and the sun sometimes shone.

Ocean salinity has been stable for millions of years, most likely as a consequence of a chemical/tectonic system which recycles the salt. Since the ocean's creation, sodium is no longer leached out of the ocean floor, but instead is forming sedimentary layers on the ocean beds. One theory is that [[plate tectonics]] result in the salt being forced under the land masses, where it is again leached to the surface.

[[Image:Salt collector in Lake Retba.jpg|thumb|Manual salt collection in [[Lake Retba, Senegal]]]]

[[Image:Dead Sea, Jordan 02.jpg|thumb|Salt deposits on the shores of [[Dead Sea]], Jordan]]

The dilute brine of the sea was largely evaporated by the sun. In Roman areas, this was done using [[ceramic]] containers known as [[briquetage]].<ref name="Murphy2009"/> Workers scraped up the concentrated salt and mud slurry and washed it with clean sea water to settle impurities out of the now concentrated brine. They poured the brine into shallow pans (lightly baked from local marine [[clay]]) and set them on fist-sized clay pillars over a peat fire for final evaporation. Then they scraped out the dried salt and sold it.

[[File:Turks and Caicos Islands raking salt stamp 1938.jpg|thumb|Raking salt depicted on a 1938 [[Turks and Caicos Islands]] postage stamp]]

In traditional salt production in the [[Visayas Islands]] of the [[Philippines]], salt are made from [[coconut husk]]s, [[driftwood]], or other plant matter soaked in [[seawater]] for at least several months. These are burned into ash then seawater is run through the ashes on a filter. The resulting brine is then evaporated in containers. [[Coconut milk]] is sometimes added to the brine before evaporation. The practice is endangered due to competition with cheap industrially produced commercial salt. Only two traditions survive to the present day: [[asín tibuok]] and [[túltul]] (or dúkdok).<ref name="Reynaldo">{{cite news |last1=Reynaldo |first1=Jerricho |title=Guimaras: The Sweet Taste of Summer |url=http://asiantravelermagazine.com/guimaras-the-sweet-taste-of-summer/ |access-date=19 December 2018 |work=asianTraveler |archive-url=https://web.archive.org/web/20181219183506/http://asiantravelermagazine.com/guimaras-the-sweet-taste-of-summer/ |archive-date=19 December 2018 |url-status=dead }}</ref><ref>{{cite web |title=Food for Thought: Do You Know The Guimaras Ingredient Tultul? |url=https://www.bitesized.ph/do-you-know-the-guimaras-ingredient-tultul/ |website=Bitesized.ph |access-date=19 December 2018}}</ref>

In the [[European colonization of the Americas|colonial New World]], Africans were enslaved and brought to rake salt on various islands in the [[West Indies]], [[Bahamas]] and particularly [[Turks and Caicos Islands]].

Today, salt labelled "sea salt" in the US might not have actually come from the sea, as long as it meets the FDA's purity requirements.<ref name="Wolke2008">{{cite book|last=Wolke|first=Robert L.|title=What Einstein Told His Cook: Kitchen Science Explained|url=https://books.google.com/books?id=8Lyrh2JXWuoC&pg=PA52|access-date=10 December 2012|date=17 October 2008|publisher=W. W. Norton & Company|isbn=9780393329421|page=52}}</ref> All mined salts were originally sea salts since they originated from a marine source at some point in the distant past, usually from an evaporating shallow sea.<ref>{{Cite web |last=Nutrition |first=Center for Food Safety and Applied |date=2022-09-23 |title=Guidance for Industry: Colored Sea Salt |url=https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-colored-sea-salt |access-date=2023-06-01 |website=U.S. Food and Drug Administration |language=en}}</ref>

==Taste==

[[File:Black Salt.jpg|thumb|upright|Black lava salt]]

Some gourmets believe sea salt tastes better and has a better texture than ordinary table salt.<ref>[http://www.slate.com/id/2117243/ "Worth One's Salt" by Dan Crane, Salon, Apr 2005]</ref> In applications that retain sea salt's coarser texture, it can provide a different [[mouthfeel]], and may change flavor due to its different rate of [[solvation|dissolution]]. The mineral content also affects the taste. The colors and variety of flavors are due to local clays and algae found in the waters the salt is harvested from. For example, some boutique salts from Korea and France are pinkish gray and some from India are black. Black and red salts from Hawaii may even have powdered black lava and baked red clay added in.<ref>Wolke, Robert L. What Einstein Told His Cook. (2002) pp. 49–50.</ref> Some sea salt contains [[sulfate]]s.<ref>{{Cite book|url=https://books.google.com/books?id=_R00NqWST6MC&pg=PA248 |title=Encyclopedia of Chemical Processing and Design: Volume 51 - Slurry Systems: Instrumentation to Solid-Liquid Separation|last=McKetta|first=John J. Jr.|date=13 March 1995|publisher=CRC Press|isbn=9780824726027|language=en}}</ref> It may be difficult to distinguish sea salt from other salts, such as pink [[Himalayan salt]], [[Salt Mines of Maras|Maras salt]] from the ancient Inca hot springs, or rock salt ([[halite]]) {{Citation needed|date=November 2022}}.

Black lava salt is a marketing term for sea salt harvested from various places around the world that has been blended and colored with [[activated charcoal]]. The salt is used as a decorative [[condiment]] to be shown at the table.<ref>{{Cite web |last=Weber |first=Shannon |title=Black Lava Salt Might Be Your New Favorite Finishing Salt |url=https://www.feastmagazine.com/recipes/article_b586ad46-c6f3-11e6-9dbb-d3e343fb9f66.html |access-date=2022-05-01 |website=Feast Magazine |language=en}}</ref>

==Health==

{{Further|Health effects of salt}}

[[Image:Saltmill.jpg|thumb|upright|A salt mill for sea salt]]

The nutritional value of sea salt and table salt are about the same as they are both primarily [[sodium chloride]].<ref name="mayo">{{cite web | url=http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/sea-salt/faq-20058512 | title=Sea salt vs. Table salt: What's the difference?|publisher=Mayo Clinic|author= Katherine Zeratsky|date=2019}}</ref><ref>{{cite web|url=http://www.abc.net.au/health/talkinghealth/factbuster/stories/2010/11/23/3073792.htm|title=Is sea salt better for you than regular table salt?|publisher=ABC Life, Australian Broadcasting Corporation|date=18 June 2019}}</ref> Table salt is more processed than sea salt to eliminate minerals and usually contains an additive such as silicon dioxide to prevent clumping.<ref name=mayo/>

[[Iodine]], an element [[Essential nutrient|essential for human health]],<ref>Fisher, Peter W. F. and Mary L'Abbe. 1980. Iodine in Iodized Table Salt and in Sea Salt. ''Can. Inst. Food Sci. Technolo. J.'' Vol. 13. No. 2:103–104. April</ref> is present only in small amounts in sea salt.<ref>{{cite journal|last=Dasgupta|first=Purnendu K. |author2=Liu, Yining |author3=Dyke, Jason V.|title=Iodine Nutrition: Iodine Content of Iodized Salt in the United States|journal=Environmental Science & Technology|date=1 February 2008|volume=42|issue=4|pages=1315–1323|doi=10.1021/es0719071|pmid=18351111 |bibcode=2008EnST...42.1315D }}</ref> [[Iodised salt]] is table salt mixed with a minute amount of various salts of the element iodine.

Studies have found some [[microplastics|microplastic]] contamination in sea salt from the US, Europe and China.<ref>{{citation | title = Sea salt around the world is contaminated by plastic, studies show | url = https://www.theguardian.com/environment/2017/sep/08/sea-salt-around-world-contaminated-by-plastic-studies | newspaper = The Guardian | date = 8 September 2017 | last1 = Glenza | first1 = Jessica }}</ref> Sea salt has also been shown to be contaminated by fungi that can cause food spoilage as well as some that may be [[Mycotoxin|mycotoxigenic]].<ref>{{cite journal|last=Biango-Daniels|first=Megan N. |author2=Hodge, Hodge T.|title=Sea salts as a potential source of food spoilage fungi|journal=Food Microbiol.|date= February 2018|volume=69|pages=89–95|doi=10.1016/j.fm.2017.07.020|pmid=28941913 |doi-access=free}}</ref>

In traditional Korean cuisine, [[jugyeom]] ({{Lang|ko|죽염}}, 竹鹽), which means "bamboo salt", is prepared by roasting salt at temperatures between 800 and 2000&nbsp;°C<ref name="soilpollu">{{cite book |author=James V. Livingston |title=Agriculture and soil pollution: new research |publisher=Nova Publishers |year=2005 |pages=45 |isbn=978-1-59454-310-4 }}</ref> in a [[bamboo]] container plugged with mud at both ends. This product absorbs minerals from the bamboo and the mud, and is claimed to increase the [[clastogen|anticlastogenic]] and [[mutagen|antimutagenic]] properties of the fermented soybean paste known in Korea as ''[[doenjang]]''.<ref name="AsianFood">{{cite book |author1=Shahidi, Fereidoon |author2=John Shi |author3=Ho, Chi-Tang |title=Asian functional foods |publisher=CRC Press |___location=Boca Raton |year=2005 |pages=575 |isbn=978-0-8247-5855-4 }}</ref> However, these claims are not substantiated by high-quality studies.

==See also==

* [[Bath salts]]

* [[Brine mining]]

* [[History of salt]]

* {{portal-inline|Food}}

* {{portal-inline|Oceans}}

== References ==

{{reflist|2}}

==External links==

* {{Commons category-inline|Sea salt}}

{{Salt topics}}

{{Authority control}}

{{DEFAULTSORT:Sea Salt}}

[[Category:Chemical oceanography]]

[[Category:Edible salt]]