That watery liquid on your yoghurt is whey — doctor says don't pour it away

Gastroenterologist Joseph Salhab explains that the watery liquid that appears on top of yoghurt after opening is whey — a natural component of the product, not a sign that it has gone off. Many people instinctively pour it away, which the doctor says is a mistake. He recommends simply stirring the whey back into the yoghurt before eating.