Wash the sauerkraut, put in boiling salted water and simmer for 1 hour. The water should have completely evaporated by the end of that time. Put the sauerkraut in a saucepan with the melted butter and stir for a few minutes over the fire, mixing well. Serve with boiled gammon or bacon. Sometimes a potato purée is served with it, or a purée of white or green beans.