Arrange yoghurt, herbs and salt in layers in a cheese cloth until all ingredients are used. Close tightly with string. Hang in cellar temperature for 24 hours, over a bowl to collect the dripping water.
Prepare brine (6% salt per weight) in a suitable container. Transfer cheese (without removing the cloth), to the brine and let sit for another 24 hours.
Cover a brie-style cheese box (or other container) loosely with baking paper. Gently unwrap the cheese cloth and transfer the cheese the to paper, pressing slightly to suit the box. Place a sprig of rosemary on top, close paper tight and cover with a lid. Keep for four weeks in refrigerator.