The tea is brewed very strongly - much stronger than most teas - using a mix of tea leaves and sometimes tea dust. It is then strained through a special cloth bag called a 'silk stocking strainer' (it really does look like a silk stocking!). This straining makes the tea extra smooth and removes all the tiny leaf bits.
Evaporated milk is used instead of fresh milk because it is richer and sweeter, and it was easier to keep before fridges were common in Hong Kong. The result is a drink that is smooth, creamy and has a gentle caramel flavour from the milk.
Milk tea is served in Hong Kong's famous cha chaan tengs - a kind of local café that is uniquely Hong Kong. The cha chaan teng menu has toast with butter and jam, egg tarts, macaroni soup and of course milk tea. These places are very busy at breakfast time.
In 2020, the traditional skills of making cha chaan teng food and drinks - including milk tea - were added to Hong Kong's list of intangible cultural heritage. That means the government officially recognised it as part of Hong Kong's culture, worth passing on to the next generation.