How is balut made? How does the balut maker know when the egg is "ripe"?

Question

How is balut made? How does the balut maker know when the egg is "ripe"?

Answer 1

Its made just like a hard boiled egg.  Just simmer it in hot water for about 12 minutes (I would never eat it, would you?)  The perfectly ripe balut egg is 17 days old.

Heres all the info AND some GREAT pictures too!

http://en.wikipedia.org/wiki/Balut

Answer 2

They look at the egg using a lightbox.  The almost mature chicken will not transmit as much light through the shell as a new embryo.  Plus, it is about 19 days to almost reach maturity.