French butter dish
From Self-sufficiency
A French Butter Dish, sometimes called a French butter keeper, French butter crock or butter bell is used to keep butter fresh and soft without refrigeration. This 19th century French designed pottery crock holds the butter packed in its lid (which is held in by the surface tension), water is then added to the base. This creates an airtight seal that keeps oxygen away from the butter, thus refrigeration is not needed, and butter can be used in its soft form.
