One of the famous foods the Filipinos are known for is the "balut". It's a one-day old boiled duckling egg. The "balut" is known as an energizer to those who need strength or aphrodisiac to others. This is peddled every evening by "balut" vendors and they come together with "chicharon", fried thin slices of pork fat or skin.
Mallard duck locally known as "Pateros itik" (Anas platyrynchos) is commonly used by duck farmers in the Philippines. The eggs from this duck are processed to "balut" and salted eggs. "Balut" is an incubated egg with developed embryo of 17 to 19 days which is boiled and eaten with or without salt. It is a Filipino delicacy that commands a good price. Fresh duck eggs are also used to prepare a dessert called "leche flan" (egg custard).
According to Ti Sencia (a traditional balut-maker ), the best balut - also known as "balut sa puti" - is made by allowing the eggs to incubate from 16 to 17 days. Eighteen days is still okay, but go beyond that and the sisiw will be too large for leisurely consumption. Egg shell thickness is also a very important factor in the handling and processing of "balut" and salted eggs.
Balut-Making is considered the major tourist attraction in Pateros. The very famous industry has been handed down from generation and shares about 23.0% of the whole Pateros industry. Balut makers are mostly from Barangay Aguho.