Asam Jawa — Tamarind

Tamarind, Tamarindus indica, is a tree of tropical Africa that travelled east across the Indian Ocean in antiquity and was long established in the Indonesian archipelago before the colonial period. The Indonesian name asam jawa, the sour of Java, records how thoroughly the fruit has been absorbed into the Javanese kitchen, where it is the ordinary souring agent of the household. It is carried by the home cook and the market seller alike, sold as pressed brown blocks of pod pulp, and belongs to the wider Indonesian tradition of sour seasoning that also draws on lime, starfruit and green mango.

The fruit of Tamarindus indica is a brown, brittle-shelled pod holding a sticky, dark pulp threaded with fibres and surrounding hard, glossy seeds. In the Indonesian pantry it is bought as a block of compressed pulp with seeds and fibres still in it, or as pods in season. The pulp is not used as it comes: it is soaked in warm water, worked with the fingers and strained, and the sour brown liquid is what enters the pot. The seeds and fibre are discarded. Young green pods are also used for their sharper sourness.

Tamarind is taken in sour vegetable soups such as sayur asam, in fish cooked in a sour broth, in sambal, in peanut sauces and in the sweet-sour dressings of rujak. It meets palm sugar, chilli, shallot and shrimp paste, and these are its natural company because its sour is rounded and fruity and needs sweetness and salt to stand upright. It is the quiet acid under strong, rich ingredients, lifting coconut milk and fatty fish without the sharpness of lime.