Cover them with water, and stew it slowly for an hour, skimming it well.
Keep the lid close, except when you are skimming off the fat.
Keep the pan closely covered, except when you are skimming it.
Skim them well, and keep the kettle covered when you are not skimming.
Boil it slowly for two or three hours, skimming it carefully.
As the whey rises, dip it off with a ...