At what level of breakdown a Haram thing could be considered Halal? What is metamorphosis?.How can we know that this process has been done completely?

Respected Muftee sahib, As you have specified in one of your Fatwa(http://islam.tc/ask-imam/view.php?q=83) that Geletin from the Pork(or any other Non-Zabiha) becomes Halal after complete metamorphosis process. What is metamorphosis?. How can we know that this process has been done completely? Is there a Hadith which states approximately as: that the thing which is Haram its constituents are also Haram, if this Hadith is there then at which level of breakdown of a Haram thing is it applicable?. Are ingredients of Pork or any other Haram thing, Halal at microlevel? what is this level of Breakdown? Why are not some extracts of Pork allowed?. Kindly guide in this regard as early as possible because we have lot of problems in slecting the Halal things which we can eat in Gremany, due to lot of Mashkook ingredients in them. JazaakAllah Khairan.