Media playback is unsupported on your device Media caption Rajini Vaidyanathan and Shilpa Kannan on whether the growing popularity of coffee in India will take over the love for traditional tea

Starbucks has announced it is to open its first outlet in India by the end of the year, marking the international chain's first venture into the country. India has been a nation of tea drinkers for centuries, but in the past decade coffee has been on the rise. Is the chai losing out to the cappuccino?

At a small stand next to a photocopying shop, Ram Shankar Patidar is heating milk on a single gas stove. The focus of his attention is a stainless steel container, which is bubbling and rattling as he adds tea leaves, water, spices, and freshly crushed ginger.

Patidar has been making and selling Indian tea, better known as chai, for more than 40 years.

He has occupied the same spot in a busy suburban business district in Mumbai for more than a decade, but for the past eight weeks there's been a new addition to the street.

Directly opposite his stand is a branch of India's largest coffee chain, Cafe Coffee Day, abbreviated by many to CCD.

"They don't make much of a difference to me," he says as he ladles the mixture through muslin into a small glass. "Those who can afford to go to CCD would anyway. It's much more expensive than what I sell."

How to make chai Heat 350ml water and 100ml of milk with four black peppercorns, 10 lightly crushed green cardamom pods, a good pinch of green fennel seeds, a small piece of cinnamon stick and a teaspoon of peeled and chopped fresh ginger

Boil gently for 15 minutes, until reduced to a large cupful

Add a teabag and brew for a minute, or longer

Strain into a cup and add sugar or salt to taste

For many years, the humble chai wallah has been part of the country's fabric, but in the past decade, the makeshift roadside stalls have begun facing competition from Western-style coffee chains.

The first Cafe Coffee Day opened in 1996, marking the beginning of a change in Indian tastes and habits. The CCD chain is now opening a branch almost every week, and has more than 1,200 stores across India. It's been joined by other chains, including Barista Lavazza and Costa Coffee.

Like their Western counterparts, India's coffee shops serve a range of coffees from mochas to lattes, iced coffees to espressos. But their appeal is greater than their beverages.

"I go to coffee shops just to hang out," says Zain Waris, a student in Mumbai. "In India, we don't have many places to hang out, and these chains don't have any objections to us spending hours and hours sitting there."

India's coffee culture has changed the way young Indians socialise.

In a country where there is a limited bar culture, and where drinking alcohol is still frowned upon in many circles, it has provided an acceptable and safe outlet for people, particularly young Indians, to share a drink.

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It is common to see large groups of teenagers congregating at coffee shops later into the evening. Some branches provide guitars for jam sessions.

It has also helped facilitate the country's growing dating culture - having a girlfriend or boyfriend at a young age is frowned upon by many, so secret trysts at a coffee shop have become the norm for many young Indians, and serve as a suitable bolthole away from the prying eyes of parents.

For 22-year-old graduate Ronak Mehta it's the perfect place to discuss college work. "It's much better than sitting on a bench, where you'd drink tea," he says.

With more than half of the country's population under 25, and a rising middle-class that is well aware of Western trends, there's little wonder Indian coffee consumption has doubled in the past 15 years since the first cafes were opened.

Image caption Dashrat Rathod (right): People like me just drink up and go

"Earlier you had generally had coffee at home or the office. These new businesses have made the cafe culture more accessible, thus attracting a young crowd who could hang out in a relaxed atmosphere," says Anil Dharker, a leading columnist and social commentator in India.

Even before the coffee chain revolution, coffee had a strong presence in South Indian homes. Typical South Indian coffee, or kapi, is a made with boiled milk and plenty of sugar, and is served in stainless steel tumblers. Many families drink more kapi than tea.

"We used to have coffee at home every morning," says Dashrat Rathod, an engineer from Karnataka. "I've never been to a coffee shop, people like me don't have the time to spend there, we drink up and go."

Rathod might have a taste for coffee but isn't prepared to pay for a serving in a new style coffee shop. The price of tea or coffee from a roadside stand is usually in the order of five rupees (about 10 US cents, or 6p), compared with around 80 rupees ($1.60, £1) upwards for a cappuccino or equivalent. This price barrier makes the coffee shop culture mainly a preserve of the upper middle classes in India.

The entrance of Starbucks, an American chain, into the Indian coffee market follows other international coffee brands such as Costa, Gloria Jeans, and Lavazza which has bought into Indian chain Barista. Like other Western brands, these tend to be seen as aspirational to many young Indians, says Anil Dharker.

Image caption Cafe Coffee Day or CCD began the coffee invasion in 1996

Even so, he says, Starbucks and others may have to work to accommodate Indian tastes.

"What actually happens is that a foreign player sees a commercial opportunity and enters a new market. And then adapts. This is particularly so of the Indian market. Just take a look at McDonalds, it's a completely different entity here," says Dharker.

Starbucks globally does already serve its own brand of "Indian" tea, the chai tea latte, but it's a world away from the unique taste of authentic Indian chai. It remains to be seen whether this will be an offering in the Indian stores.

But despite the coffee invasion, tea remains popular, with consumption rising from 562,000 tonnes annually to 837,000 tonnes in the last 15 years.

"More people are drinking tea because they like it, and because the population is rising," says Surjit Patra from the Indian Tea Association.

The average Indian drinks now around 250 cups of tea per year. This is quite a low figure by international standards - in Ireland, for example, the average citizen drinks 1,000 cups per year - suggesting there could be room for further expansion.

"We have found lots of health benefits in tea," Mr Patra says, unsurprisingly extolling the virtues of the drink he promotes. "There's no other beverage like it. Not even coffee."

Additional reporting by Aarti Thobhani.