Re: how to prepare a well fermented yogurt at home

No!

First you must boil the ENTIRE quantity of milk - to kill unwanted bacterias - up to 82 degrees Celsius (118 F - buy a cooking thermometer). Wait until the milk temperature came down to 48 degrees C(118 F - if too hot, you will kill the bacterias) . Then you add fresh yogurt (with live bacteria) or the bacteria themselves (if so stir the bact. in a small quantity of milk first then add the remaining). Put in a tupperware or a jar - Cover with a towel - to keep the temperature right ( I do mine in a Rice cooker and this keeps it warm) for 4 hours - if it remains at the proper temperature (40-46 degrees C 105-115 F) [rice cooker or yogurt maker will give you the right temperature] - leave overnight , if you simply use the towels.

Put it the fridge and enjoy!