Kashk

The yogurt is boiled first and fermented afterwards, which is the reverse of how yogurt is made.

Vegetarian, but not vegan — contains dairy (yogurt).

Ingredients

• 2 kg sour full-fat yogurt
• 2 teaspoons salt

Method

1. THE YOGURT IS BOILED FIRST AND FERMENTED AFTERWARDS, WHICH IS THE REVERSE OF HOW YOGURT IS MADE. Yogurt is milk fermented and then kept cold; this takes yogurt, kills the culture by boiling it, and then lets a second fermentation happen in the drained solids. Its article gives the order plainly: sour yogurt is blended until smooth, boiled, and strained; it is then left to ferment in a warm oven for several days; the moisture is strained off again and the solids are blended with salt. That second fermentation is why kashk tastes of something sharper and older than yogurt, and it is why you cannot shortcut it by simply salting strained yogurt.
2. IT IS BLENDED BEFORE IT IS BOILED. Two kilos of sour yogurt whisked or blended completely smooth. Lumps survive the boil and end up as grains in the finished paste.
3. THE BOIL IS WHAT SEPARATES IT. Brought up stirring, and held at a gentle boil for ten minutes: the proteins coagulate and pull away from a thin greenish whey. Then poured into a muslin-lined sieve and left to drain for two hours.
4. THE FERMENT IS A WARM HOLD FOR THREE DAYS, NOT A COOK. The drained solids go into a bowl, covered with a cloth, somewhere steadily warm -- about 40C, an oven with only the light on. Three days. It will smell strongly sour by the end, which is the point, and it should smell sour rather than putrid.
5. IT IS DRAINED A SECOND TIME AND THEN SALTED. More liquid will have come out. Strain it off, then beat in two teaspoons of salt. The salt is a preservative as well as seasoning and it is what makes the paste keep.
6. THE LIQUID THAT DRAINS OFF HAS ITS OWN NAME AND USE. Its article records the drained liquid being made into qaraqurut, dried black whey, rather than thrown away.
7. IT IS SOLD AS A THICK LIQUID OR AS HARD DRIED LUMPS, AND THE DRIED KIND MUST BE SOAKED. Its article is specific that the dried form needs soaking and softening before it can be cooked with. If you have bought the hard white discs, break them up, cover with warm water for two hours and blend; the jarred liquid kind is ready to use and is what the other pages here assume.
8. IT IS NEVER BOILED IN A DISH. This is the one rule that matters when using it rather than making it: it has already been boiled and fermented, and reheating it to a boil makes it seize into grains that will not come back. It goes in off the heat. Three pages here depend on it -- Aush Reshteh, Kashk Bademjan and Kalehjoosh.
9. IT CAN BE SHAPED AND DRIED FOR KEEPING. Its article notes it is rolled into balls, sliced into strips or formed into chunks and left to dry. Dried hard it keeps for a year, which is the reason the stuff exists.

Our own recipe. This one was written for this site rather than taken from anywhere, so there is no source to point you at. The quantities and the order of the steps are choices, not the only way to do it.

Filed under Iran · All recipes