Workers harvest traditional fish sauce from thousands of colourful clay pots in a Vietnamese village. They follow a meticulous seven step cycle to complete the recipe. It can take up to two years for some batches to fully mature.

Photographer Ngoc Diem, 42, lives in Ho Chi Minh City but often visits the village in the Ham Tien ward of Phan Tiet City, in the Binh Thuan province, as he is so inspired by the smells and colours of the production process.