Black salt is also known as Kala namak. It is a special type of Indian mineral salt with a distinctive / sulfurous flavor. Black salt or Kala Namak is not black, but more a reddish-gray, because of the presence of trace minerals and iron. It is not interchangeable with sea salt or table salt because of its distinct flavor.
According to India’s classical medical science, Ayurveda, black salt is full of therapeutic benefits. It is rich in iron, and is a cure for flatulence. It is considered a cooling spice in ayurvedic medicine and is used as a laxative and digestive aid. It is also believed to relieve intestinal gas and heartburn. It is sometimes used by people with high blood pressure or on low-salt diets because it is thought to be lower in sodium and purportedly does not increase sodium content in the blood.
The most common of this “spice” is to impart the special characteristic flavor to the tangy fresh salads called Chats. It is also regularly used in small quantities in chutneys, raita, pickles and many other savory Indian snacks, adding a very different flavor than just using regular salt. Try sprinkling it on fresh cut fruit such as apples and bananas for a delicious treat. Can also be used to replace sea salt or salt. Black salt is appreciated by vegans in dishes that mimic the taste of eggs. It is used, for example, to spice tofu to mimic an egg salad.