Kala Namak - Production

Production

The raw material for producing kala namak was originally obtained from natural halite from mines in Northern India and Pakistan in certain locations of the Himalayas salt ranges, or from salt harvested from the North Indian salt lakes of Sambhar or Didwana.

Traditionally, the salt was transformed from its raw natural forms into commercially sold kala namak through a reductive chemical process that transforms some of the sodium sulphate in the raw salt into pungent hydrogen sulfide and sodium sulfide. This involves firing the raw salts in a furnace for 24 hours while sealed in a ceramic jar with charcoal along with small quantities of harad seeds, aamla, bahera, babul bark, or Sajji. The fired salt is then cooled, stored, and aged prior to sale. Kala namak is prepared in this manner in Northern India with production concentrated in the Hisar district, Haryana. The salt crystals appear black in colour, and are usually ground to a fine powder which is pink in colour.

Although the kala namak can be produced from natural salts with the required impurities, it is common to now manufacture it synthetically. This is done through combining ordinary sodium chloride admixed with smaller quantities of sodium sulphate, sodium bisulphate and ferric sulphate, which is then chemically reduced with charcoal in a furnace. Reportedly, it is also possible to create similar products through reductive heat treatment of sodium chloride, 5-10 percent of sodium carbonate, sodium sulphate, and some sugar.