Reserve one-sixth of the measured water and keep it cool. Put the rice and the remaining five-sixths of the water in a saucepan. Bring to a simmer and cook for 20–25 minutes, until the rice is very soft; allow longer if needed. Keep the reserved water cool.
Whisk the yogurt, egg yolk, flour and reserved cool water in a bowl until smooth and free of flour lumps.
Gradually whisk several ladles of hot rice water into the yogurt mixture. Slowly pour it back into the saucepan while stirring.
Warm the yogurt mixture gradually before combining it with the pot.
Cook over gentle heat for 8–10 minutes, stirring, until the soup lightly thickens and reaches at least 160°F on a food thermometer. Avoid a vigorous boil. Add salt to taste.
The soup remains smooth and pourable, with very tender rice and no raw flour taste.
Melt the butter in a small pan. Lower the heat, stir in the dried mint and pul biber, and warm briefly until fragrant without scorching. Spoon over the hot soup and serve.
Warm the recipe's spices in fat until fragrant, then stop before they scorch.
Cool leftovers quickly in shallow containers, ideally within 1 hour, and refrigerate. Use within 24 hours; reheat only once, stirring until steaming hot throughout.
Cooking guidance
Plain full-fat unstrained yogurt makes a smooth, pourable soup. Temper it with hot rice water before adding it to the pan, then stir gently rather than letting the soup boil hard.
Tiny rice-and-lamb balls, chickpeas and tender lamb in a yogurt broth finished with mint butter. Gaziantep yuvalama is a substantial celebratory dish, often described locally as a meal rather than an everyday soup. This home adaptation uses rice flour for the small balls; traditional preparations may grind soaked rice with meat.
Slow-simmered beef-bone broth made silky with yogurt, egg yolk and lemon, with garlic and a light dried-mint finish. This terbiyeli version turns homemade beef-bone broth into a smooth, lightly tangy soup. A terbiye is the whisked yogurt, egg-yolk and lemon mixture added gradually to the hot broth; a little flour helps it hold together.
An Afyon soup of whole green lentils and thin dried erişte noodles, with onion, tomato paste and flour. A little mint butter can be spooned over each bowl.