There’s a natural separation between the curds and whey when yogurt is made, and once it’s packaged and left sitting for a while, whey naturally separates, creating a watery substance on top of the curds. According to Amanda Sauceda, RDN, “There‘s tons of nutritional value in whey...It’s rich in protein,” so while you may prefer to dump it out, there is only added value to mixing it in.