New Delhi, Aug. 5 -- "Egg coffee, eww!" That was my first thought when I heard about Hanoi's famous brew. As a coffee devotee (snob), I prefer my drink black and unsweetened. But I will try anything once, so on a Vietnam holiday a few years ago, I visited Hanoi's old quarter to sample the concoction. The frothy coffee arrived in a ceramic cup that sat in a bowl-like saucer with hot water (to keep the drink warm). I stirred the cup and gulped down the drink, which tasted like an airy, coffee-flavoured custard.

French colonists brought coffee to Vietnam in the mid 19th-century. Today, the country is the world's second-largest Arabica coffee producer (after Brazil) and the largest producer of Robusta coffee. The Vietnamese introduced local ...