Start by making sure each jar is thoroughly cleaned out and sterile for the storage of pig's feet Give the pig's feet a good washing with cool water Cook the pig's feet. Put the feet in a large pot and add enough water to cover the meat. Over medium-high heat, bring the water to a rolling boil. Reduce the heat to a low simmer and cook pig's feet for about 1 hour and 30 minutes, or until tender. Make sure to stir during the boiling process often. Use a slotted spoon or tongs to remove pig's feet from water. Rinse feet under hot water to remove excess fat and foam. Remove as many visible bones as possible so that you can fit the feet in jars Rewash your large pot to cook your pickled vinegar. Estimate about how much vinegar will need to cover the pig's feet and add the vinegar to the pot (you will add the feet later after your pickled vinegar is done). Put onions, bay leaves, peppercorns, cloves, mustard seeds, coriander seeds, and 2 slices of ginger root into the pot.