Wash the pork skin, chicken bones, and chicken feet. Blanch them by placing in a pot with cold water, bring to a boil, then turn off the heat. Remove and rinse them for later use.

Tip 1: Simmer until the water level is about 2/3. If needed, add hot water to maintain the water level to prevent the gelatin from becoming too hard.

Tip 2: If you have leftover gelatin, store it in the freezer.

Tip 3: If the gelatin doesn't set well after cooling (indicating insufficient collagen), add some agar strips, bring the liquid to a boil again, and let it cool.