text: why does milk moves upwards on boiling.?   because it is separating, there is two main parts to milk, the fat and the milk/water. when you boil the milk the fat rises to the top separating itself from the thiner milk liquid....and then it curdles, so don't eat it too much like that....and use whipping cream instead of milk, it holds much longer, and if your using a cream or a milk base, remember (if it's a soup or a sauce of some sort) to add a little bit of strach, i.e. corn starch or flour, in order to hold it all together, this is called a rue.