Cook · Fish

Maasor Muror Khar

মাছৰ মূৰৰ খাৰ

Fish head and raw papaya cooked with kolakhar — the alkaline dish that opens an Assamese meal, and the one that made me want to understand the chemistry.

Chandan Baruah·12 August 2026·4 min read

Maasor Muror Khar — fish head cooked with khar and vegetables, served in a brass bowl.
01

The story

The first time I made khar on my own it tasted of soap. Not slightly — properly, unmistakably of soap, in the way that makes you put the spoon down. I had used too much kolakhar and boiled it hard, and I spent the next week convinced the dish was simply not very good.

It is very good. I was the problem. Khar is a genuinely alkaline preparation and, like anything alkaline, it works in a narrow band: enough to change the texture of the papaya and round out the fish, not so much that you are tasting the reagent itself.

Learning to hit that band is the closest thing Assamese home cooking has to a technical rite of passage.

02

About the dish

Origin
Khar takes its name from the alkali itself — kolakhar, made by burning the peel of sun-dried banana (traditionally the bhim kol variety), steeping the ash in water and filtering it until the liquid runs clear.
Region
Throughout Assam, with strong household variation in strength and vegetable.
Cultural significance
Khar is the first dish of a full Assamese meal — served before everything else, in small quantity, eaten with rice. It is also one of the very few genuinely alkaline savoury preparations in Indian cooking, which is why it has almost no analogue elsewhere.
Flavour profile
Savoury and faintly slippery in the mouth, with a soft mineral roundness. It is not sour, not hot, and not spiced in any conventional sense.
03

Ingredients

The khar

  • 3–4 tbsp kolakhar (filtered banana-ash alkali) strength varies enormously — start low

The dish

  • 2 fish heads rohu, split
  • 1 tsp turmeric
  • 1 tsp salt
  • 3 tbsp mustard oil
  • 300 g raw papaya peeled and cut into 2 cm cubes
  • 2–3 green chillies slit
  • 500 ml water
  • to taste salt

To finish

  • a few coriander leaves

Substitutions & notes

  • Bottle gourd, ash gourd or even a handful of lentils can replace the papaya. The papaya is traditional because it holds its shape against the alkali.
  • Commercial bottled kolakhar is widely sold and perfectly good, but its strength is inconsistent between brands. Taste and adjust; never measure blind.
  • There is no substitute for kolakhar itself. Baking soda is chemically adjacent and gastronomically nothing like it — it will give you an unpleasant metallic dish.
04

Method

  1. Step 01

    Prepare

    1. Rub the fish heads with turmeric and salt. Leave for 15 minutes.
    2. Peel and cube the papaya. Keep the pieces generous — small ones disintegrate in the alkali.
  2. Step 02

    Fry the fish

    1. Heat the mustard oil to smoking point, rest it briefly, then fry the fish heads until well coloured on both sides. Take them out.
    2. Traditional khar is cooked without onion or garlic. It looks like an omission. It is not — the alkali and the aromatics work against each other, and the dish is cleaner without them.
  3. Step 03

    Cook the papaya

    1. In the same oil, add the papaya and green chillies with a pinch of salt. Turn them in the oil for two minutes.
    2. Add the water and half the kolakhar. Simmer, uncovered, until the papaya is tender and has taken on a slight translucence — about 15 minutes.
  4. Step 04

    Bring it together

    1. Return the fish heads. Add the remaining kolakhar a spoonful at a time, tasting between additions. Stop while it still tastes like food rather than like a reagent.
    2. Simmer gently for a further eight to ten minutes so the liquid reduces and thickens very slightly. It should be loose, not saucy.
  5. Step 05

    Finish

    1. Off the heat, scatter the coriander.
    2. Serve first, in a small portion, with plain rice — before anything else on the table.
05

Palateful notes

What I learned

  • Add the khar in two stages. Front-loading it means committing to a strength before the dish has told you what it needs.
  • Alkali softens plant tissue fast. Papaya that would take twenty minutes in water can collapse in eight here.
  • The soapy note is the alkali itself. If you can taste it, the answer is dilution and a little more salt, not more cooking.

Common mistakes

  • Measuring kolakhar by the recipe rather than by taste. Homemade and bottled strengths differ by a factor of several.
  • Adding onion or garlic out of habit. It muddies a dish whose whole character is clarity.
  • Hard boiling. It drives the alkaline note forward and breaks the fish.

Variations

  • Khar Diya Dail — the same principle with pulses instead of fish, and the version most households cook on ordinary days.
  • Omita Khar, with papaya alone, is the everyday vegetarian form.

What I would change next time

I want to make kolakhar from scratch and measure the pH of each batch, so I can finally speak about "strength" with a number attached instead of a shrug. That experiment is the subject of the Roots piece on khar.

  • Assamese
  • Khar
  • Alkaline
  • Fish
  • Traditional
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