Line a strainer with two layers of cheesecloth. In a medium bowl, mix together the yogurt, salt, pepper and garlic.
Pour into the cheesecloth lined strainer. Place the strainer over another bowl to catch the liquid, and refrigerate for 1 to 2 days, until all of the liquid has drained off. Empty the drainage bowl occasionally so you can see when the cheese has stopped draining.
Transfer cheese to a covered container, and store in the refrigerator for up to two weeks.