Tamarind

Tamarind is one of Thailand’s main sources of sourness, along with lime. Its sourness is rounder and fruitier than lime juice, and it gives sauces body and colour as well as tang.

Sour and sweet tamarind

The tamarind tree grows all over Thailand, and its brown pods come in two kinds. Sour tamarind (makham priao) is used for cooking. Sweet tamarind (makham waan), especially from Phetchabun province, is eaten as a snack straight from the pod. For cooking, you want the sour kind, sold as a block of pressed pulp, called makham piak (“wet tamarind”).

Making tamarind water

Break off about 50 g of pulp and cover it with 150 ml of warm water. Leave it for 15 minutes, then squeeze and mash it with your fingers until the pulp comes away from the seeds and fibres. Push it through a sieve, scraping the underside of the sieve with a spoon. The thick, brown liquid is what recipes call tamarind concentrate or tamarind water. Use less water for a thicker paste.

How to cook with it

It is the sour backbone of pad Thai sauce, melted with palm sugar and fish sauce. In massaman curry it balances the richness of coconut and the sweetness of palm sugar and peanuts. In the south, it sours fish curries and gaeng som. It also goes into dipping sauces: jaew, the dark Isaan dip for grilled meat, and nam jim for grilled chicken.

Buying and storing

Blocks of pulp keep for a year in a cool cupboard, wrapped. Tamarind water keeps for about a week in the fridge, and freezes well in ice-cube trays.

Ready-made concentrates in jars and tubs vary hugely in strength and some add sugar or vinegar. Indian “tamarind concentrate” is often much darker and stronger than Thai tamarind water. Taste before you use them and start with less.

Substitutes

Lime juice with a little brown sugar gives sourness without the fruitiness. In a pinch, a mixture of lime juice and a little Worcestershire sauce (which itself contains tamarind) works in pad Thai.

Cook’s tip

Make a batch of tamarind water and freeze it in an ice-cube tray. One cube is roughly two tablespoons, which is the amount most recipes ask for.