It's the summer of 2015. I am pacing a tea shack situated at a corner of Robinson street in central Kolkata, waiting for an important interview. Behind me are props that make the tea shop so essentially Kolkatan: a faded poster of a Tollywood blockbuster sharing wall space with that of Rabindranath Tagore, a transistor and an assortment of biscuits in glass jars.

Nerves are frayed. This is an important interview, things depend on it.

"Chaa kheye nin (Have your tea)," says the man, handing me the bhaar of muddy brown tea.

Source: Premankur Biswas

I take a sip, and everything falls into place. Like the fatigued dancer in those popular tea advertisements of the 1990s, I am a changed person. Confident, brash and ready to take on the world.

Not really. But you get the picture.

A cup of chai or cha, as it's known in east India, may not be the magic potion popular culture makes it out to be, but it does act like a mild shot of adrenaline for the Bengali bhadralok.

Which is why, when The Guardian declared that the best street in India is Kolkata's chai, I wasn't surprised.

"Fires are stoked and fanned, spices crushed, sugar added, tea and milk poured from ever greater and more improbable heights, always with a grin and a flourish before it all comes together in a tiny, crudely formed clay cup. The dusty pink clay lends its own character to the drink, which, with its malty tea, warming masala, creamy buffalo milk and generous dose of sugar, seems to straddle the line between food and beverage," says William Battle in his glowing tribute to the humble Kolkata cha.

If you have walked down the bustling pavements of Kolkata, you know what Battle is talking about. If you have lived in Kolkata long enough, cha probably runs in your veins. If you have lived in Kolkata all your life, your stomach is probably ruined by the rivers of hard-boiled tea you have had at roadside stalls all over the city. Remember a certain Tridib from Amitav Ghosh's Shadow Lines?

Its side-effects notwithstanding, cha in Kolkata is entwined to its fluctuating fortunes.

How did the city end up being the tea capital of the country ?

According to this article in Teabox.com, commercial tea plantations were first established under the British Rule when a native variety of Camellia Sinensis plant was discovered by Scottish traveller Robert Bruce in 1823 in the Northeastern region of India or the present state of Assam.

According to Dinesh Prakash, former tea planter with the Williamson Magor group, Bruce carried out an expedition in Assam to look for tea bushes.

"He found a fierce tribe there that consumed tea as a medicinal plant," says Prakash.

The sample Robert Bruce collected from this region were tested in Calcutta (sent by his brother Charles Bruce soon after Robert’s demise in 1830) and found to be tea, although a variety different from the Chinese plant.

According to Teabox.com, the tea industry in India started to take shape around early 1840. Chinary tea plants, which were first tried out in Assam, were later tested in high-elevation regions of Darjeeling and Kangra, and it was here that they grew far more healthily.

Tea planting in Darjeeling officially began in 1841. Many others began experimenting with tea in much the same way. By 1847, an official tea plant nursery was established in Darjeeling. Soon after, the first commercial plantation of Darjeeling, Tukvar Tea Estate, was established in the year 1850.

A tea storage unit in Assam in the late 1850s/ Source: Teabox.com

And Kolkata was at the centre of all this.

"The best tea came to Kolkata because of its proximity to both Assam and Darjeeling," says Prakash.

Kolkata also benefited because of it was the commercial capital of the country for most of early 20th century.

"Most of the tea auctions took place here," Rudra Chatterjee of Luxmi Tea Company, which owns the renowned Makabari brand, says.

But Indians were not initiated into tea culture till mid-20th century. "Most of the tea manufactured here was shipped off to England," says Prakash.

It was in the 1940s that the British woke up to the business prospect of tea in India.

"They realised that if they get Indians hooked into tea, they would benefit a lot," Prakash says.

"Free bread with tea."

The New Orphan Tea shop at Kolkata's office para (district), is an after work stop for most babus. Post 6 pm, a diligent queue of regulars forms in front of the shop. It's a democratic queue where Darjeeling (the most expensive variety) doesn't get precedence over CTC (the cheaper tea dust variety).

Source:New Orphan Tea, Kolkata

Sandip Biswas reigns supreme over this world of plywood chests. He has been handling the counter for about two decades now.

"Though the shop changed many hands, I know that it was formed sometime in 1860s. Our initial customers were Englishmen. It was only in the 1930s that the British government decided to popularise the beverage among Indians. That's when they started offering incentives like free loaves of bread along with a 100 gm of tea. Obviously, Kolkatans are suckers for freebies," Biswas says.

Ubiquitous tea stalls started mushrooming around Eastern part of the country only later. Kolkata, however, already had a niche tea culture. "Delhi didn't have tea shops till late into 1950s," says Prakash.

"Since Kolkata was also the most important commercial port, there were tea stalls to satiate the needs of British officials even about 90 years ago. Surat too had a tea culture then, because it was also a flourishing port city," says Chatterjee.

"Tea was considered to be against Hindu scriptures"

In filmmaker Rituparno Ghosh's adaptation of Rabindranath Tagore's Chokher Bali, which was set in early 20th century Bengal, one of the character's obsession with tea has a comical aftermath.

Rajlakshmi, an ageing Hindu widow has developed an obsession with tea but feels guilty about it.

"I will go to hell for having that firangi drink," she laments.

"It's true, Bengali Hindus for the longest time had reservations about drinking tea because it was considered to be impure. But the bhadralok's urge to emulate the British genteel culture took over. They soon developed a taste for the beverage, and by 1950s, tea stalls started mushrooming all over the city," says Prakash.

The perfect blend

So what goes into Kolkata tea that makes it so special?

"The blend that most tea stall owners in Kolkata use is a mix of Doars and Assam CTC," Chatterjee of Luxmi Tea Company says.

When it comes to quality, tea is broadly divided according to the region it comes from.

"Each tea bush is unique in its own way. However, tea produced in the Darjeeling, which has a more subtle flavour, is considered to be the best tea in the world. Tea from Assam has its own unique qualities. But CTC Assam, which are small pellets of the crushed tea, have a strong flavour and is more full bodied," Prakash says.

A mix of CTC and Doars, another variety of tea from north Bengal, is also viable from most tea stall owners because of the high 'cuppage' factor.

"From one kilo of this tea, you can easily make around 500 cups of tea or more. Some tea stall owners make around 800 cups too," Biswas from the New Orphan tea shop says.

However, in certain parts of north Kolkata, a mix of the Darjeeling (Fannings variety) is also used.

"It's specifically in the College Street area that tea stall owners use this mix. However, it is blended with CTC," Chatterjee says.

Ramkhilam Pandit, who runs a tea shop in the Fancy Lane area of Central Kolkata for the past two decades , manages to decode the magic of Kolkata tea.

"I use fresh buffalo milk for the tea. But at times I use packet milk too. I ensure that the tea isn't too milky or too watery. There is a balance. The tea leaves also have to soak in for the right amount of time. Yet, if you ask me, why is my stall always full of people, I will tell you that it's about the people. People make the tea here," he says.