Persian Style Whey or Kashkam Whey. Kashk is a traditional Iranian dairy product made from concentrated whey. It has a rich, tangy taste and is used as a key ingredient in Persian stews, soups, and sauces, adding depth and a unique savory flavor. It can be used as a substitute for sour cream in various dishes. The jar contains 470g (16.6 oz) of Kashk.