A heady cocktail of scents fills the air as one enters the narrow lanes of the historic city of Kannauj, the perfume capital of India in Uttar Pradesh state.
But one smell stands out – petrichor, the earthy redolence of the first rains on dry soil that perfumers in the city capture in tiny bottles.
From poets to farmers desperately waiting for rain to feed their crops, the pleasant smell resonates with a wide variety of people awaiting the joy of relief from the hot Indian summers.
Perfumers in Kannauj have tapped into this emotion and mastered the art of bottling this soothing scent in an oil-based fragrance called "mitti attar".
Mitti means soil in Urdu and attar means perfume in Persian.
The town of 2.3 million, about 120km from the state capital Lucknow, is home to an attar cottage industry.
From rose, jasmine and sandalwood to oud, musk and saffron, about 350 small, medium and large perfumeries make attars following a centuries-old process, in huge large copper cauldrons using flowers, clay and oils distilled in water over wood fires.
There are about 400 attar perfumeries in the city but only 10 per cent of them make the mitti attar, according to the government-run Fragrance and Flavour Development Centre.
Gaurav Mehrotra, a third-generation perfumer, operates one of them.
His grandfather started Puja Perfumery about 45 years ago, he says, and the family still produces the perfume in a unit behind his home in Kannauj.
While the history of attar goes back about 60,000 years, the fragrant oils were made popular during the time of the Mughals, the Muslims who ruled the subcontinent for about 300 years, starting in the late 15th century.
The rulers and their queens were known to have used attar to keep their minds fresh and bodies scented in the hot climate.
With modernisation and globalisation, Indians were exposed to synthetic perfumes and global brands that led to a decline in the popularity and sales of attar.
But Mr Mehrotra says that with awareness and growing interest in natural products, more people, particularly women and customers from abroad, are buying attar, especially the mitti attar.
The natural perfume is used as a fragrance, an air freshener, an essential oil, and in aromatherapy, because of its soothing smell.
There has also been a growing demand from abroad, including countries such as the US, UK, Europe and Japan, the perfumer said.
“It was made earlier also but in the last five to 10 years, its popularity has grown manifold," Mr Mehrotra said.
"Women particularly like it because of its subtle fragrance. Foreigners also like it because it is natural and traditional."
While the perfume smells of rain, the monsoon is the most unsuitable month for making it.
The process involves baking clay extracted from topsoil, which during the rainy season can lose its natural smell because of an excess of moisture.
Making mitti attar is a painstaking, time-consuming process.
Perfumers use unglazed clay that is extracted from the topsoil and baked in a kiln, often sourced from local potters.
It is then crushed and thrown into a "deg" – a traditional large copper cauldron – and sealed with a lid using clay.
The cauldron is kept on a furnace made of bricks and clay, and fuelled by firewood or coal.
A bamboo pipe leads from the cauldron to a "bhapka" – a receiving vessel with a long neck and round belly, also made of copper, that is kept in a cooling tank of water and acts as a condenser. It holds liquid paraffin as a base oil.
As the cauldron boils, the vapour from the vessel passes through the bamboo to the receiver.
The fire is kept burning for a few hours after which the first distillate is transferred to an empty copper pot and distilled again. The mitti attar is extracted in the second distillation.
The process is called hydro-distillation. The longer the process, the stronger the perfume is, Mr Mehrotra said.
“We use raw, broken clay," he said. "We start with 20kg of clay and add 40kg of water for steam. The receiver already has a base oil such as sandalwood or carrier oil.
"The process continues. We throw the used clay and add a new batch and double the water. The process continues for two to three months."
Once extracted, the perfume is stored in pouches made of camel leather, which absorb the moisture and further concentrate the fragrance.
The perfumes are priced according to their quality and strength. Sandalwood base oil costs a lot more than liquid paraffin, for example, Mr Mehrotra said.
“The price of a bottle can vary from 40 rupee [about 50 cents] to 1,000 rupee for 10ml, depending on the base oil used,” he said.