Bhaga Tenga Fermented Rice

Ingredients

• - 2 cups sour fermented rice water (from poita bhat)
• - 1 onion
• - 1 tsp mustard oil
• - 2 green chillies
• - Salt
• - Fresh coriander

Method

1. About Bhaga Tenga: This is a uniquely Assamese sour curry that turns the leftover water from poita bhat (overnight-fermented rice) into a probiotic-rich tangy curry. It is a beautiful example of zero-waste cooking — what would be discarded elsewhere becomes a refreshing dish for hot weather.
2. Make or source poita bhat first: Bhaga Tenga starts with poita bhat. The night before, cook 1 cup rice. Place in a clay or glass bowl. Pour over enough cold water to fully submerge the rice by about 2cm. Cover loosely and leave at room temperature overnight (8-10 hours).
3. Check fermentation: By morning, the rice will have softened and the water will have a faintly sour smell — pleasantly tangy, not unpleasant. If it smells off or has visible mould, discard and start over. The sourness is from natural lactic acid bacteria.
4. Separate the sour water: Place a sieve over a bowl. Pour the entire poita bhat through. The sour water that drains off — about 2 cups — is what you need for this recipe. The strained rice can be eaten separately as breakfast with salt and mustard oil.
5. Prepare the aromatics: Take 1 medium onion. Finely chop into small dice. Take 2 green chillies. Slit lengthwise and finely slice. Roughly chop 2 tbsp fresh coriander and set aside for garnish.
6. Heat the mustard oil: Pour 1 tsp mustard oil into a small heavy-bottomed pan or kadhai. Place over medium-high heat. Heat for about 30 seconds until it just begins to smoke and the harsh raw smell mellows. This step is essential — raw mustard oil tastes bitter and sharp.
7. Fry the onion: Reduce heat to medium. Add the chopped onion and fry for 4-5 minutes, stirring often, until the onion turns soft and translucent with the edges just beginning to turn golden. Do not let the onion brown deeply — you want it sweet and soft, not caramelised.
8. Add the green chilli: Add the slit green chillies to the pan and stir for 30 seconds. The chillies will sizzle and release their aroma into the oil.
9. Pour in the sour rice water: Pour the 2 cups of strained sour rice water into the pan slowly to avoid splattering. The hot oil will hiss as it meets the cold liquid.
10. Bring to a gentle simmer: Increase the heat slightly and bring to a gentle simmer — small bubbles around the edges, not a rolling boil. Vigorous boiling can break the natural emulsion and turn the curry watery.
11. Simmer for body: Continue simmering uncovered for 12-15 minutes. The curry will reduce slightly and develop a thicker, almost milky-looking body. The sour edge will mellow and round out as the heat works on it.
12. Season carefully: Add salt to taste — start with 1/2 tsp and adjust. The fermented water already has its own flavour, so do not over-salt. Some Assamese cooks add a tiny pinch of sugar to balance the sourness; this is optional.
13. Garnish and serve: Switch off the heat. Sprinkle the chopped fresh coriander over the top. Pour into bowls and serve hot alongside steamed rice. Bhaga Tenga is traditionally drunk almost like a soup at the start of the meal, before the heavier dishes, to wake up the appetite.