Black Salt (Kala Namak): The Kiln-Fired Indian Salt With an Eggy Smell

That eggy note in chaat masala, or in a good tofu scramble? It’s black salt, or kala namak, the Indian salt that smells of sulfur. It’s made by firing ordinary salt with charcoal or plant material, which turns some of its sulfate into sulfide. And despite the name, once it’s ground it isn’t black at all but reddish-gray to pink. Don’t confuse it with black lava salt, which is sea salt colored with charcoal.

At a glance

How it is made

The clearest description we found comes from an Indian court. In 1970, the Allahabad High Court had to decide whether black salt counted as salt for sales tax. The manufacturer in the case said he mixed Sambhar salt with charcoal and heated it. The court also quoted Satya Prakash’s Advanced Inorganic Chemistry: black salt is made mostly in northern India, chiefly in Hissar district, from common salt with a little sajji and chebulic and emblic myrobalans. Sodium sulfate is a necessary ingredient, and the organic matter partly reduces it to sulfide during fusion. The same text says you can make it in a lab by fusing common salt with a little sodium carbonate. The court held that this black salt was salt in the ordinary sense, a product of common salt.¹

A sample in a 2016 Swiss government analysis listed its ingredients as 95% salt and 5% Salsola stocksii.³ The two descriptions don’t match, and we found no source on how most producers make it today.

Is it volcanic, or Himalayan? You’ll often see black salt described as a volcanic salt mined in the mountains of Pakistan alongside Himalayan pink salt. None of the sources we read backs that up. The court record describes a fired product made from ordinary salt, and the manufacturer in the case used Sambhar salt.¹ We found no source that says which salt most producers start from.

Flavor and the compounds behind it

Black salt is mostly sodium chloride. The Swiss sample was 38.7% sodium and 57.9% chloride, close to plain salt.³⁴ What sets it apart is sulfur. The Swiss report credits its characteristic sulfuric taste to a high hydrogen sulfide content of about 200 mg/kg, the same figure the German Federal Institute for Risk Assessment (BfR) reported from a 2003 sample.³² The taste is eggy, and it’s so pungent that you’ll want to use it sparingly. It stinks until you cook it, and an unknown amount of the gas escapes while you do.

You’ll often read that the color comes from iron sulfide. The passages of the chemistry text quoted by the court mention reduction to sulfide but don’t say which compound gives the color, and the Swiss analysis measured iron (0.36 g/kg) without tying the color to it.¹³ We couldn’t confirm the iron sulfide explanation from a source we could open.

Origin and history

Black salt is often said to have been first described by the Ayurvedic physician Charaka around 300 BC. We couldn’t trace that to a source we could open, so we’re leaving it out. The 1970 court record shows it being made commercially in northern India and sold as salt.¹

How black salt is used

Chaat masala. This is its best-known job. It’s a key component. See chaat masala.

Drinks. It lifts salted lassi and jaljeera.

Finishing. It works as a finishing salt, a pinch or two added just before serving. Try it with seafood, in South Asian masalas and on steak.

Vegan egg flavor. That eggy smell is why plant-based cooks add it to tofu scrambles and egg-free dishes.

Chutneys, raitas, fruit and snacks. Cooks also use it in chutneys and raita, on cut fruit and on popcorn.

Buying and quality

Ground black salt is pinkish to gray, not black: anywhere from reddish-gray to pink to purple. Expect a strong sulfur smell when you open the jar. That’s the point of it.

Storage

We found no shelf-life figure for black salt from a regulator or standards body. Keep it in a closed container, partly to keep the smell in, and away from moisture.

Safety and health

Hydrogen sulfide. In 2003, the BfR looked at a black salt with about 200 mg/kg of hydrogen sulfide. It said it couldn’t make a firm statement on the toxicological relevance, but concluded that black salt used as intended in Indian cooking poses no health risk to consumers, mainly because intake is low, the salt is used sparingly and some of the gas escapes during cooking.²

Sodium. Black salt sometimes gets described as lower in sodium than table salt. The one sample in the Swiss analysis was 38.7% sodium,³ and table salt is about 40% sodium,⁴ so it’s not a meaningful sodium cut. The FDA’s Daily Value for sodium is less than 2,300 mg a day,⁵ and the World Health Organization recommends adults stay under 2,000 mg a day, naming raised blood pressure as the main health effect of eating too much.⁶

Minerals and contaminants. The same sample had 1.3 g of potassium and 0.3 g of calcium per kilogram. The Swiss report concluded that specialty salts generally add less than 2% to recommended daily intakes of other minerals and don’t have nutritional properties that would justify recommending them as a standard choice. Of the 25 salts it analyzed, the kala namak sample had the second-highest arsenic concentration (106 µg/kg). The report puts the high levels in Himalaya and kala namak salts down to likely natural contamination. It compared contaminant levels with health-based intake benchmarks and didn’t report any sample going over them.³ These figures come from one sample.

Iodine. Specialty salts usually aren’t iodized,⁷ and the Swiss kala namak sample held only 22 µg of iodine per kilogram.³ If you count on salt for iodine, keep iodized salt around too.

Health claims. Black salt often gets credited with easing indigestion, bloating, heartburn and breathing complaints. We found no regulator or systematic review that supports any of these, and we’re not making any such claim.

Substitutes and comparisons

• Black salt substitutes
• Chaat masala, chaat masala substitutes and chaat masala vs. garam masala
• Black lava salt
• Himalayan salt, rock salt, table salt
• Asafoetida, another sulfurous seasoning of Indian cooking