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, [1] solar salt, [2] or simply salt. Like mined rock salt, production of sea salt has been dated to prehistoric times.
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. [3]
Concentration of ion in sea water [3] | mg/l |
---|---|
Chloride | 18 980 |
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 |
Sea salt is mentioned in the Vinaya Pitaka, a Buddhist scripture compiled in the mid-5th century BC. [4] 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 and other warm, dry climates. [5]
Such places are today called salt works, instead of the older English word saltern. An ancient or medieval saltern was established where there was:
In this way, salt marsh, pasture (salting), and salt works (saltern) enhanced each other economically. This was the pattern during the Roman and medieval periods around The Wash, in eastern England. [6] There, the tide brought the brine, the extensive saltings provided the pasture, the fens and moors provided the peat fuel, and the sun sometimes shone.
The dilute brine of the sea was largely evaporated by the sun. In Roman areas, this was done using ceramic containers known as briquetage. [6] 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.
In traditional salt production in the Visayas Islands of the Philippines, salt are made from coconut husks, 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). [7] [8]
In the colonial New World, slaves were brought from Africa 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. [9] 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. [10]
Some gourmets believe sea salt tastes better and has a better texture than ordinary table salt. [11] 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 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. [12] Some sea salt contains sulfates. [13] It may be difficult to distinguish sea salt from other salts, such as pink Himalayan salt, Maras salt from the ancient Inca hot springs, or rock salt (halite) [ citation needed ].
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. [14]
The nutritional value of sea salt and table salt are about the same as they are both primarily sodium chloride. [15] [16] Table salt is more processed than sea salt to eliminate minerals and usually contains an additive such as silicon dioxide to prevent clumping. [15]
Iodine, an element essential for human health, [17] is present only in small amounts in sea salt. [18] Iodised salt is table salt mixed with a minute amount of various salts of the element iodine.
Studies have found some microplastic contamination in sea salt from the US, Europe and China. [19] Sea salt has also been shown to be contaminated by fungi that can cause food spoilage as well as some that may be mycotoxigenic. [20]
In traditional Korean cuisine, jugyeom (죽염, 竹鹽), which means "bamboo salt", is prepared by roasting salt at temperatures between 800 and 2000 °C [21] 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 anticlastogenic and antimutagenic properties of the fermented soybean paste known in Korea as doenjang . [22] However, these claims are not substantiated by high-quality studies.
Brine is water with a high-concentration solution of salt. In diverse contexts, brine may refer to the salt solutions ranging from about 3.5% up to about 26%. Brine forms naturally due to evaporation of ground saline water but it is also generated in the mining of sodium chloride. Brine is used for food processing and cooking, for de-icing of roads and other structures, and in a number of technological processes. It is also a by-product of many industrial processes, such as desalination, so it requires wastewater treatment for proper disposal or further utilization.
Sodium chloride, commonly known as edible salt, is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chlorine ions. It is transparent or translucent, brittle, hygroscopic, and occurs as the mineral halite. In its edible form, it is commonly used as a condiment and food preservative. Large quantities of sodium chloride are used in many industrial processes, and it is a major source of sodium and chlorine compounds used as feedstocks for further chemical syntheses. Another major application of sodium chloride is deicing of roadways in sub-freezing weather.
Lake Grassmere / Kapara Te Hau is a New Zealand waituna-type lagoon in the northeastern South Island, close to Cook Strait. The lake is used for the production of salt.
Iodised salt is table salt mixed with a minute amount of various salts of the element iodine. The ingestion of iodine prevents iodine deficiency. Worldwide, iodine deficiency affects about two billion people and is the leading preventable cause of intellectual and developmental disabilities. Deficiency also causes thyroid gland problems, including endemic goitre. In many countries, iodine deficiency is a major public health problem that can be cheaply addressed by purposely adding small amounts of iodine to the sodium chloride salt.
A salt evaporation pond is a shallow artificial salt pan designed to extract salts from sea water or other brines. The salt pans are shallow and expansive, allowing sunlight to penetrate and reach the seawater. Natural salt pans are formed through geologic processes, where evaporating water leaves behind salt deposits. Some salt evaporation ponds are only slightly modified from their natural version, such as the ponds on Great Inagua in the Bahamas, or the ponds in Jasiira, a few kilometres south of Mogadishu, where seawater is trapped and left to evaporate in the sun.
Salt, also referred to as table salt or by its chemical formula NaCl, is an ionic compound made of sodium and chloride ions. All life depends on its chemical properties to survive. It has been used by humans for thousands of years, from food preservation to seasoning. Salt's ability to preserve food was a founding contributor to the development of civilization. It helped eliminate dependence on seasonal availability of food, and made it possible to transport food over large distances. However, salt was often difficult to obtain, so it was a highly valued trade item, and was considered a form of currency by many societies, including Rome. According to Pliny the Elder, Roman soldiers were paid in salt, from which the word salary is derived, although this is disputed by historians. Many salt roads, such as the Via Salaria in Italy, had been established by the Bronze Age.
In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as rock salt or halite. Salt is essential for life in general, and saltiness is one of the basic human tastes. Salt is one of the oldest and most ubiquitous food seasonings, and is known to uniformly improve the taste perception of food, including otherwise unpalatable food. Salting, brining, and pickling are also ancient and important methods of food preservation.
Fleur de sel or flor de sal is a salt that forms as a thin, delicate crust on the surface of seawater as it evaporates. Fleur de sel has been collected since ancient times, and was traditionally used as a purgative and salve. It is now used as a finishing salt to flavor and garnish food. The origin of the name is uncertain, but is perfectly in line with both meanings of fleur:flower, and the surface of something. The salt crust forms flower-like patterns of crystals which may contribute to the name.
A saltern is an area or installation for making salt. Salterns include modern salt-making works (saltworks), as well as hypersaline waters that usually contain high concentrations of halophilic microorganisms, primarily haloarchaea but also other halophiles including algae and bacteria.
Bristol Lake is a dry lake in the Mojave Desert of San Bernardino County, California, 42 km (26 mi) northeast of Twentynine Palms.
Curing salt is used in meat processing to generate a pinkish shade and to extend shelf life. It is both a color agent and a means to facilitate food preservation as it prevents or slows spoilage by bacteria or fungus. Curing salts are generally a mixture of sodium chloride and sodium nitrite, and are used for pickling meats as part of the process to make sausage or cured meat such as ham, bacon, pastrami, corned beef, etc. Though it has been suggested that the reason for using nitrite-containing curing salt is to prevent botulism, a 2018 study by the British Meat Producers Association determined that legally permitted levels of nitrite have no effect on the growth of the Clostridium botulinum bacteria that causes botulism, in line with the UK's Advisory Committee on the Microbiological Safety of Food opinion that nitrites are not required to prevent C. botulinum growth and extend shelf life..
A sabkha is a coastal, supratidal mudflat or sandflat in which evaporite-saline minerals accumulate as the result of semiarid to arid climate. Sabkhas are gradational between land and intertidal zone within restricted coastal plains just above normal high-tide level. Within a sabkha, evaporite-saline minerals sediments typically accumulate below the surface of mudflats or sandflats. Evaporite-saline minerals, tidal-flood, and aeolian deposits characterize many sabkhas found along modern coastlines. The accepted type locality for a sabkha is at the southern coast of the Persian Gulf, in the United Arab Emirates. Evidence of clastic sabkhas are found in the geological record of many areas, including the UK and Ireland. Sabkha is a phonetic transliteration of the Arabic word used to describe any form of salt flat. A sabkha is also known as a sabkhah,sebkha, or coastal sabkha.
Sociedad Química y Minera de Chile (SQM) is a Chilean chemical company and a supplier of plant nutrients, iodine, lithium and industrial chemicals. It is the world's biggest lithium producer.
Cured fish is fish which has been cured by subjecting it to fermentation, pickling, smoking, or some combination of these before it is eaten. These food preservation processes can include adding salt, nitrates, nitrite or sugar, can involve smoking and flavoring the fish, and may include cooking it. The earliest form of curing fish was dehydration. Other methods, such as smoking fish or salt-curing also go back for thousands of years. The term "cure" is derived from the Latin curare, meaning to take care of. It was first recorded in reference to fish in 1743.
Bittern, or nigari, is the salt solution formed when halite precipitates from seawater or brines. Bitterns contain magnesium, calcium, and potassium ions as well as chloride, sulfate, iodide, and other ions.
Himalayan salt is rock salt (halite) mined from the Punjab region of Pakistan. The salt, which often has a pinkish tint due to trace minerals, is primarily used as a food additive to replace refined table salt but is also used for cooking and food presentation, decorative lamps, and spa treatments. The product is often promoted with unsupported claims that it has health benefits.
Pickling salt is a salt that is used mainly for canning and manufacturing pickles. It is sodium chloride, as is table salt, but unlike most brands of table salt, it does not contain iodine or any anti caking products added. A widely circulated legend suggested that iodisation caused the brine of pickles to change color. This is false; however, some anti-caking agents are known to collect at the bottom of the jars or cause the brine to cloud, a minor aesthetic issue. Pickling salt is very fine-grained, to speed up dissolving in water to create a brine, so it is useful for solutions needing salt.
Salt in Chinese history including salt production and salt taxes played key roles in economic development, and relations between state and society in China. The lure of salt profits led to technological innovation and new ways to organize capital. Debate over government salt policies brought forth conflicting attitudes toward the nature of government, private wealth, the relation between the rich and the poor, while the administration of these salt policies was a practical test of a government's competence.
Brine mining is the extraction of useful materials which are naturally dissolved in brine. The brine may be seawater, other surface water, groundwater, or hyper-saline solutions from several industries. It differs from solution mining or in-situ leaching in that those methods inject water or chemicals to dissolve materials which are in a solid state; in brine mining, the materials are already dissolved.
Asín tibuók is a rare Filipino artisanal sea salt from the Boholano people made from filtering seawater through ashes. A related artisanal salt is known as túltul or dúkdok among the Ilonggo people. It is made similarly to asín tibuók but is boiled with gatâ.