Indian black salt has a faintly sulphurous and smokey flavour which disappears during the cooking process. Unsurprisingly, kala namak is the best salt for use in Indian cuisine, especially North Indian cooking, and is traditionally used in making salt blends like chaat masala and the summer drink, jal jeera. Alternative names are black salt, kala loon, kala namak and sanchal.
Kala namak is a true rock salt, found in large large halitedeposits formed through evaporation of ancient seas and is mined from locations in the Pakistani Himalayas. It is then imported into India where it is converted to kala namak by heating to around 900C in the presence of natural reductive agents (usually either gum Arabic - Vachellia nilotica - or Salsola stocksii) until it melts, then it is cooled, stored and aged. The final kala namak consists mainly of sodium chloride, with trace impurities of sodium sulphate, iron sulphide and hydrogen sulphide. The sodium chloride gives kala namak its saltiness, the iron sulphide the purple-pink colour and the sulphur compounds the distinctive sulphurous aroma that some say is like rotten eggs, or to me is more of a volcanic flavour. For further information, look at kala namak on Wikipedia.
Kala namak is good in traditional Indian cuisine like chaat masala, potato chaat or chaat puri, or why not make Indian squash curry or why not try and make vegan poached eggs with it!
Allergen information: Packed in a factory that handles mustard, sesame and gluten.