In a country that has two seasons — dry and wet — and the consistently high temperatures of perpetual summer, it’s no wonder that iced coffee, or cà phê dá, is the staple drink throughout Vietnam. While the drink is consumed as a hot beverage in the morning, mugs are swapped for tall glasses full of ice as the sun approaches its zenith, an effort to chill the coffee and combat the relentless heat and humidity of the climate.

Vietnamese iced coffee is as complicated as you make it; it is served and enjoyed in a variety of ways depending on the proclivities of the drinker. In its most basic form, it’s made using a medium- to coarse-ground dark roast, usually a robusta bean that is low in acidity and high in bitterness.

Once ground, the coffee is placed in a Vietnamese drip filter and then filled with hot water. This practice is slow and thorough, which results in a surprisingly strong filter coffee. The resultant brew is then poured over a glass of ice, and that’s your basic Vietnamese iced coffee.

Another popular way of enjoying this drink is slightly unusual, at least by Western standards. While the standard coffee aficionado will almost always drink coffee black, it’s forgivable in some circumstances to mix in a splash of cold milk. The Vietnamese don’t do it this way. Instead, they eschew dairy milk and use the condensed variety. Prior to the drip-filter process, two or three tablespoons of the viscous white liquid are placed in the bottom of a glass and brewed coffee is poured on top. It is served this way to the customer, who is then expected to mix it together with a long spoon. The final product is called cà phê sữa đá (cafe soda). It’s cold and cloyingly sweet but still packs a caffeinated punch.

The reason for adding condensed milk is due to the struggle of Vietnam’s dairy industry to keep pace with its booming coffee trade during its burgeoning years. Since fresh milk was in such short supply, condensed milk was used by the French to temper the bitterness of the brew. It caught on in a big way, and to this day condensed milk is a popular addition to many types of Vietnamese coffees, including cà phê dá and cà phê trứng (cafe trung), or egg coffee.

If you’d like to make cà phê dá at home, the process is pretty straightforward. You’re going to need a Vietnamese coffee filter (which you can find on Amazon), some authentic Vietnamese coffee (Cafe du Monde or Trung Nguyen are available locally), condensed milk of any brand, a glass of ice, and a halfway decent kettle. Simply follow the instructions above, take your time, and when it’s ready, prepare yourself for a sweet and gratifying cold coffee drink.