Milk is boiled (if only pasteurized warm). Allow to cool to a temperature that allows to keep calm his little finger (45 C). Insert sea salt (maybe another) and stir to dissolve. Add yogurt and yeast drops. Mix well, close the lid and wrapped in a blanket for 4-5 hours. Pour into a cheesecloth and placed exuding 4-5 hours. puree can be left to be drained all night, then gets thick. Store in refrigerator.