An egg coffee (Vietnamese: Cà phê trứng) is a Vietnamese drink traditionally prepared with egg yolks, sugar, condensed milk and robusta coffee. The drink is made by beating egg yolks with sugar and coffee, then extracting the coffee into the half of the cup, followed by a similar amount of "egg cream" — egg yolks which are heated and beaten, or whisked.
The drink is served in cafes throughout Vietnam, though it originates in Hanoi. The Giang Café (Vietnamese: Cà Phê Giảng) in Hanoi is known for serving the drink, which it makes with chicken egg yolk, coffee powder, condensed milk, and, optionally, cheese. The cup is sometimes served inside a bowl of hot water or set upon a small candle to retain its temperature. The son of the café's founder Nguyen Giang claims that his father developed the recipe for the drink when milk was scarce in Vietnam in the late 1940s, replacing the dairy product with egg yolk.
Ingredients for making coffee include fresh chicken eggs, sugar, milk, and coffee. The egg yolks are hand-whipped with milk and sugar, and then boiled. Hot or iced coffee is poured into the beaten eggs, which will form an aromatic foam. A teaspoon is provided in order to eat the foam before drinking the coffee at the bottom.
Egg coffee is contained in a small cup. To keep the drink warm, the waiter puts a cup of coffee in a bowl of warm water. After being poured over the cream made from eggs, the coffee at the bottom of the cup acquires a richer taste. In the past, eggs were just hand-beaten, so it took time and the foam of the eggs could not be achieved. Now, after the eggs have been smoothed with the machine, hot or iced coffee is added, together with cocoa eggs, egg white beans and matcha (tea powder) eggs. It can be served either hot or iced.
There are other, different, recipes for coffee containing egg.