New Delhi, Feb. 14 -- On a late November afternoon last year, I found Prateek Didwania pottering about behind an Astoria Storm Espresso Machine inside an Art Deco bungalow on Kolkata's Ray Street. It was just before he and his partners Aditya Ladsaria and Piyush Kankaria opened the doors to Yours Truly Coffee Roasters, a 15,000 sq ft cafe cum experience centre. The smell of fresh paint mingled with the aroma of coffee as Didwania brewed a fresh cup for me. We took a tour of the seating areas, coffee classroom, roastery, and kitchen, where experts from Bengaluru's Lavonne Academy were training the staff.

Over the past decade, Kolkata has witnessed a proliferation of cafes that serve up a litany of beverages like frappes and lattes and oth...