Yes it is possible to make yogurt, and it is very easy to do. You will need milk, and plain yogurt. Take the milk and heat it until warm (160-180 degrees F). Add a few spoon fulls of the plain yogurt and stir. Cover and let it sit in a warm spot over night. The bacteria in the yogurt acidify the milk which thickens it. If you add powdered milk to the warm milk it will make a thicker yogurt. Alternativley you can use a yogurt starter culture in place of the yogurt.