Balut is a fertilized developing egg embryo that is boiled and eaten from the shell. It is commonly sold as street food in the Philippines. The length of incubation before the egg is cooked is a matter of local preference, but generally ranges between 14 and 21 days.
Penoy is an unfertilized duck egg without yolk formation when screened against a lighted candle or electric bulb also known as the candling process. These eggs are kept warm in a rice husk for a few days before boiling."