Kashk (also Kishik) is a form of dried yogurt used all over the middle east and central Asia as an ingredient. Sour Trahana is a second dried milk product used in Greece and the middle east. Where I live, I can purchase sour trahana, but not kashk.
How should I substitute trahana in recipes that call for kashk? Say, for example, in a soup recipe like ones that use kashk as a topping, or ones that use kashk as a base? What adjustments should I make?