This tonic is so refreshing in the heat: Nuoc sam, a type of drink prepared from herbal plants, is one of the most popular drinks of Asians when the heat is at its worst. In Ho Chi Minh City, nuoc sam is usually sold from handcarts vendors set up on the pavements along busy streets.

Under the scorching sun, passers-by buy a glass of nuoc sam to satisfy their thirsts before continuing on their way in the middle of a throng of vehicles or pedestrians.

This drink is usually divided into four types: rong bien (seaweed), bong cuc (chrysanthemum), mia lau (dwarf sugarcane) and nuoc dang (bitter-flavored water). A glass of nuoc sam costs from VND1,500 to VND3,000. Apart from nuoc dang, the drink is usu­ally served with ice.

You can also find nuoc sam at night-time on the streets in Cholon in District 5, better known as Ho Chi Minh City's Chinatown. A difference is that nuoc sam in the evening is served at a warm temperature instead of with ice.

Nuoc sam is usually prepared from those herbal plants said to be good for health like ma de (plan­tain), mia lau (dwarf sugarcane), hat duoi uoi (seeds of duoi uoi fruit) and bi dao (winter melon). After brewing the ingredients, a little sugar is added to make it easier to drink. To brew nuoc sam with a bit­ter flavor, or nuoc dang, people usually add other ingredients like artichoke, pennywort, chrysanthe­mum, and la-kwa. Nuoc dang is said to be helpful for those who suffer from constipation and high blood pressure.

Many residents of Ho Chi Minh City are addicted to this type of tonic because it is also a delicious drink. If you are a foreigner visiting Vietnam, ask for a glass of nuoc sam and you will understand why this drink is so popular among Asians.