Bone cooking method: usually, the tube bone is dried and preserved. When it is made, it is first smashed into small pieces, then put into a pot and boiled in water to kill germs. After staying overnight, remove the oil floating on the water, then take out the bone to dry and grind it into bone powder.
Steaming bone method: knock the dry bone into pieces, then put it in a pressure cooker and drown it with water, then cover it tightly and heat it. When the temperature reaches 120℃, the fire can be turned off after boiling for 24 hours, the upper layer of fat is removed after boiling the next day, the bone is taken out, dried and crushed.