6 years! According to this 2 hours should've been enough :
Tortoise Shell and Chicken Bone Soup with Walnut Kernels
Ingredients
Tortoiseshell 30g, shin bone of black chicken 2, walnut kernels 10, salt to taste.
Preparation
1. Crack the tortoiseshell and chicken bones, and place in a pot with an adequate amount of water. Stew over a low fire for approximately 2 hours.
2. Add the walnut kernels and salt and continue to stew until the walnut kernels become soft. Add more salt to taste and serve.
haha your twisted