You do need to make your own whey for this recipe. You can do this with either raw milk or plain yogurt. If you are using raw milk, simply pour the milk into a jar, lightly cover it, and leave it at room temperature for 5-7 days, until it fully separates, then use a strainer to separate the curds and whey. To use plain yogurt, place two cups of plain yogurt in a cheesecloth. Tie the cheesecloth and hang it from a cupboard handle with a large bowl underneath it. Let it sit and the whey will drain into the bowl below. Leave it there for 4-8 hours.