Mattha is what is left over, and that is the whole of its character. A household that churns its own curd for white butter is left with a pale thin liquid at the bottom of the pot, and rather than throw it out the eastern plain salts it, drops in roasted cumin and a crushed green chilli, and drinks it cold with the midday meal from April onwards. It is thinner than a Punjabi chaas and far thinner than any lassi, closer to sour water than to dairy, and it is meant to be — the job is to put back the salt and the water that a morning in the sun took out, not to be a treat. Bihar drinks it in quantity, poured from a brass jug into steel tumblers and refilled without asking. Where the sweet drinks of this zone are handed to guests, mattha is what the family drinks.
INGREDIENTS
- 400 g full-fat natural yoghurt (or 400ml real buttermilk)
- 1.2 litres cold water
- 1 tsp black salt (kala namak)
- ½ tsp salt
- 1 tsp roasted cumin powder
- 1 green chilli (crushed)
- 2 cm ginger (finely grated)
- a handful of coriander leaves (chopped)
- a few curry leaves (optional)
- 1 tsp ghee (for the tempering (optional))
- ½ tsp cumin seeds (for the tempering (optional))
- ice (to serve)
METHOD
- Whisk the yoghurt in a large jug until completely smooth with no lumps.
- Add the cold water a little at a time, whisking, until you have a thin pourable liquid — about one part curd to three parts water.
- Stir in the black salt, salt and roasted cumin powder.
- Add the crushed green chilli, grated ginger and coriander.
- Taste and adjust the salt. It should be noticeably salty and sour, and not at all creamy.
- For the optional tempering, heat the ghee in a small pan, splutter the cumin seeds and curry leaves, and pour it in. Let it cool before serving.
- Chill thoroughly.
- Stir again before pouring, as it separates on standing.
- Serve very cold in steel tumblers alongside a hot meal.
