Once the yoghurt has turned, then it is best to refrigerate immediately. Otherwise, it turns more sour. The starter needs to be unflavoured yoghurt (for the information of anyone trying this). Another method which I have used is to stand the yoghurt jar on a hotwater bottle and then swaddle the lot with a doona. If adding flavour, do not belt it around in a blender with a fruit or flavouring, unless you want to return your yoghurt to a milk consistency, or close to it. While it turns, do not shake or disturb the container. During summer, best to leave in a warm place out of doors, safe from any disturbance. If you have the old style halogen downlights under the bench (as I have had), this is a good place to leave your wrapped jar as these globes emit heat. Milk powder tends to thicken the result and can be added to milk. Adding water I would never do but 100% full cream milk is all that is needed.
