Choosing beans for a phin: still robusta

A phin extracts slowly, with water sitting on the grounds for nearly four minutes. A lightly roasted arabica over-extracts and turns astringent. A dark-roasted Đắk Lắk robusta does the opposite: the longer it steeps the thicker it gets, which is what condensed milk wants.

If you are brewing at home, grind a little coarser than for espresso, rinse the phin with boiling water first, and do not tamp it hard.