Whey
The thin, greenish-yellow liquid left when milk curdles and the curd is lifted out.
Also: paneer ka paani, chhena water
Whey is the liquid part of curdled milk. It carries most of the water, most of the lactose, some minerals and the whey proteins that rennet and acid cannot set. A cheesemaker may run off nine litres of whey for each kilogram of cheese. Little goes to waste: whey is heated again to make ricotta, requesón and other whey cheeses, boiled down for Norwegian brunost, fed to pigs whose meat goes into Parma ham, and dried into whey powder. In Indian kitchens, the whey from making paneer is used to knead chapati dough, cook dal or rice, or kept sour to curdle the next batch of paneer. It is also the liquid that keeps Surti paneer and topli nu paneer moist.