20 Brilliant Ways to Repurpose Old, Spoiled Milk

16. Make cheese

Did you know that cheese is made of milk curds? Manufacturers use rennet, an enzyme found in the stomachs of calves, to coagulate the milk and separate the curds from the whey. With rotten milk, the cheese-making process is nearly complete. Just heat up the rotten liquid in a sauce pan until it reaches 185°F, stir in some white vinegar, and remove the liquids while saving the solids. After letting the curds cool in the fridge, you can use this ingredient in any way you would cottage cheese.