Kala namak
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Kala namak ("black salt" in Urdu, Urdu: کالا نمک, Hindi, Hindi: काला नमक) is a kiln-fired rock salt with a sulphurous, pungent smell used mainly in the countries of South Asia. It is also known as "Himalayan black salt", bit noon, bire noon, bit loona, bit lobon, kala loon, sanchal, kala meeth, guma loon, or pada loon, and is manufactured from the salts mined in the regions surrounding the Himalayas.
The condiment is composed largely of crystalline sodium chloride heated with charcoal and several other herbal components lending the salt its color and smell. The smell is mainly due to its sulphur content; the salt is heated in presence of many herbal components and also contains greigite Template:Chem2, Iron(II,III) sulphide). When whole, the salt is brown and black. When ground into a powder, its color may range from pink to black-brown to dark black.
Kala namak has been praised in herbal science and used for its perceived medical qualities.<ref name=MLachu/><ref name=foods>Template:Citation</ref>
Production
The raw material for producing kala namak was originally manufactured from natural halite from mines in Northern India in certain locations of the Himalayas,<ref name=mb>Template:Citation</ref><ref name=birb>Template:Citation</ref> salt manufactured from the North Indian salt lakes of Sambhar or Didwana.<ref name=DC>Template:Citation</ref>
Traditionally, the salt was transformed from its relatively colorless raw natural forms into the dark-colored commercially sold kala namak through a reductive chemical process that transforms some of the naturally occurring sodium sulphate of the raw salt into pungent hydrogen sulphide and sodium sulphide.<ref name=SC>Template:Citation</ref> This involves firing the raw salts in a kiln or furnace for 24 hours while sealed in a ceramic jar with charcoal along with small quantities of harad seeds, amla, bahera, babul bark, or natron.<ref name=DC/><ref name=SC/> The fired salt melts, the chemical reaction occurs, and the salt is then cooled, stored, and aged prior to sale.<ref>Archived at GhostarchiveTemplate:Cbignore and the Wayback MachineTemplate:Cbignore: Template:CitationTemplate:Cbignore</ref><ref name=mb /> Kala namak is prepared in this manner in northern India with production concentrated in Hisar district, Haryana.<ref name=SC/> The salt-crystals appear black and are usually ground to a fine powder that is purple.
Although kala namak may have traditionally been chemically produced from impure deposits of salt (sodium chloride) with the required chemicals (small quantities of sodium sulphate, sodium bisulphate, and ferric sulphate) and charcoal in a furnace it is now common to simply add the required chemicals to pure salt before firing. Reportedly, it is also possible to create similar products through reductive heat treatment of salt, 5-10% of sodium carbonate, sodium sulphate, and some sugar.<ref name=SC/>
Composition
Kala namak consists primarily of sodium chloride and trace impurities of sodium sulphate,<ref name=folk>Template:Citation</ref><ref name=elephants>Template:Citation</ref> sodium bisulphate, sodium bisulphite, sodium sulphide, iron sulphide, and hydrogen sulphide.
Sodium chloride provides kala namak with its salty taste, iron sulphide provides its dark violet hue, and all the sulphur compounds give kala namak its slight savory taste as well as a highly-distinctive smell, with hydrogen sulphide being the most prominent contributor to the smell. The acidic bisulphates/bisulphites contribute a mildly sour taste.<ref name="birb"/> Although hydrogen sulphide is toxic in high concentrations, the amount present in kala namak used in food is small and thus its effects on health are negligible.<ref name=birb/>
Uses
Kala namak is used extensively in South Asian cuisines of India, Pakistan, Bangladesh, and Nepal as a condiment or added to chaats, chutneys, salads, fruit, raitas, and many other savory snacks. Chaat masala, a South Asian spice blend, is dependent upon black salt for its characteristic sulphurous egg-like aroma. Those who are not accustomed to black salt may describe the smell as resembling flatulence.<ref name=MLachu>Template:Citation</ref> Black salt is sometimes used sparingly as a topping for fruits or snacks in North India and Pakistan.
Kala namak is sometimes applied to tofu in vegan egg recipes.<ref>Template:Cite web</ref>
Kala namak is considered a cooling spice in Ayurveda and is used as a laxative and digestive aid.<ref name=mb/><ref name=folk/><ref name=elephants/><ref name=jamma/> It is also been noted to relieve flatulence and heartburn.<ref>Template:Cite web</ref> It is used in Jammu to cure goiters.<ref name=jamma>Template:Citation</ref> This salt is also used to treat hysteria and for making toothpastes by combining it with other mineral and plant ingredients.<ref name=mb/> The uses for goiter and hysteria are dubious. Goiter, due to dietary iodine deficiency, would not be remedied unless iodide was present in the natural salt. In the United States, the Food and Drug Administration warned a manufacturer of dietary supplements, including one consisting of Himalayan salt, to discontinue marketing the products using unproven claims of health benefits.<ref>Template:Cite web</ref>