“The air quality index is particularly bad today,” said Ganesh Iyer, coughing. The AQI was bad, but not that bad. That day in Delhi, the AQI was between 201 and 300—much better than the 401-500 levels that the capital had seen for a week. Thanks to the odd-even scheme which began a few days ago and fast winds, the air quality was poor, not severe. That day you could see the morning sun. A week ago, in the morning, one struggled to make out the face of someone walking by. Yet Iyer coughed.

“No mask?” I asked.

“No, no, I want the Jim Carrey one,” Iyer said.

Iyer, the national sales director of Veen, a Finnish natural mineral water brand, may not be able to tell how good or bad the air is. If he has a superpower, it is to tell how good or bad the water is—from sight, smell, and taste.

Iyer is India’s only certified water sommelier.

Comparisons may be drawn between his ilk and those who can tell the finer details of wine, or tea. But there the similarities end, because telling the finer aspects of water, not to put too fine a point on it, is not for the average mortal, for what is water? An inorganic, transparent, tasteless, odourless, and nearly colourless chemical substance. See what Iyer is up against?

Read the description of a wine on the bottle. Say, “Oaked chardonnay with hints of vanilla.” Once your brain has taken in the idea, you may actually concur with the sommelier who described it when you have had a sniff and a sip: “Say, it does taste oaky with hints of vanilla.” Would you be able to tell why a certain mineral water tastes a bit chalky? Or if another kind smells like freshly-cut grass? In the first case, you can turn the bottle for product details and see that there are traces of calcium in the water. Those who pottered about in the chemistry lab longer than required in school may tell it without looking, too, but it isn’t as easy as in the case of wine, is it? Now, the smell of freshly-cut grass? That’s magnesium. What if that is the smell of some water drawn from a well? Can you tell?

Iyer can tell. He’s has been trained at the Doemens Academy in Gräfelfing, Germany. In 2018, in an 18-day programme, Iyer learned to sniff and tell the off-flavours of water and tell its mineral components. He can sip some (“for mouth feel”) and tell if that it is soft or hard. If he has the technical details such as the TDS (total dissolved solids) level, hardness, virginality (the nitrate level—the less, the better), ph-level, vintage (of the water source), and terroir (French for soil), he can say what purpose a certain kind of water is good for. “What I do is detect different attributes of water and suggest this kind of water will go well with certain foods, certain spirit, say, scotch,” he explained.

Iyer, who began his career with Evian, has more than 20 years of experience in the water industry. He had dallied with the idea of becoming a wine sommelier at times. After considerable pondering, on two counts he decided against it: there were too many, and it seemed too easy.

The training was rigorous. There’s the theory and the practical session, which includes factory visits. Then there’s the sniff-and-tell test in an isolated room to detect the properties of one sample from another. “One of the things we were taught is to check the appearance, smell, taste and after taste and say what is the sodium level in the water, or the magnesium level in the water. That’s a very difficult task, even for me, who has been in the industry for the last 25 years,” he said. “It was a pain.”

The water that Veen sells in India is bottled from a natural mineral water source in Bhutan, the world’s first and only carbon negative country. It is sold to luxury hospitality chains like Hyatt, Lodhi, Leela, and the Taj. For Iyer, knowledge about the finer aspects of water gives him an edge at work. Part of Iyer’s job is to travel across cities, sensitise people about the pros of drinking natural mineral water and hold water-food pairing sessions. Iyer says there are a discerning few who are aware of the benefits of drinking natural mineral water and approach Veen for home supply. “We have about 250 customers in Delhi,” he said.

Unbeknown to many, drinking natural mineral water does have a ton of benefits. Here are a few on the first list a Google search came up with: stronger bones, lowering bad cholesterol, beautiful skin, good for rheumatism, kidney protection, and preventing muscle cramps, etc. The mass-consumed bottled water is mostly from borewells purified by reverse osmosis. Though it is devoid of contaminants, it is devoid of the good stuff, too: minerals and good microbes. “Bacteria have got a very bad name. There are good bacteria, too, those that are good for the gut,” says Iyer. “Treated water just slakes your thirst, that’s it.”

Or maybe people do know, but it becomes a matter of cost and convenience. This is how the operations of a natural mineral water seller work: Samples are taken from sources, sent for tests prescribed by the Bureau of Indian Standards and vetted for contaminants and other characteristics. It is observed for a year and if it does not change characteristics and has no contaminants, it is approved to bear the title “natural mineral water” for sale. “The water is tested, not cleaned, so that it retains all the good minerals,” Iyer says. But it sure does not come cheap, too.

More than 20 years selling water, how has becoming a water sommelier changed Iyer’s view of the colourless, odourless liquid? “Well, it was just a product then,” he said. And now? “Did you know that water is older than earth?” he asked in a tone tinged with awe. He could ask it in no other way. About half of that precious life-sustaining liquid on the planet most of us take for granted is older than the sun itself. And the linchpin of our planetary system is about 4.6 billion years old.

The colourless, odourless liquid has saved Iyer much in medical costs, too. “I have not been to a doctor for the past 15-20 years,” he said. How? He drinks it. Lots of it.

Follow us on Facebook, Twitter & YouTube to never miss an update from Fortune India. To buy a copy, visit Amazon.