ayran

Ayran (Bos taurus, fermented milk) is used once in this library, in the jameed-free mansaf: 500 ml, which the recipe says loosens the laban. It goes into the pot with 2000 g of full-fat plain yogurt, one egg the recipe calls the stabiliser, and 30 g of cornflour, and everything is whisked smooth off the heat. The pot then goes on medium-low and the stirring does not stop while hot lamb broth is added, until the sauce reaches a gentle boil. The library lists lactic acid for ayran's clean yogurt tang.

The Journal's note on jameed says what that stirring guards against. Traditional mansaf is built on jameed, a hard ball of salted, dried fermented yogurt, and reconstituted jameed starts around pH 4 where fresh milk starts near 6.7. Acid strips the charge that keeps casein micelles apart, heat strips their protective kappa-casein, and a 2018 study showed that heated micelles clump earlier as acidity rises. Constant stirring keeps any spot from overheating, and egg or starch thickens the liquid between the clumps. The note calls this the best account of the rule, not a test of it, and reads the egg and cornflour here as the same stabilising instinct.