[T]he French Butter Dish, used to prevent butter from getting rancid without the aid of refrigeration, has [...] a variety of names; for example, the French butter crock, the French butter keeper, the French butter pot, the beurrier Breton, beurrier Normand, pot à beurre Breton and the beurrier à l'eau. - James Sloss Pottery | French Butter Dish
Our French butter dish, also called a butter bell.
The butter gets packed into the cavity.
It is then overturned into a dish with a little cold water in the bottom. Some people suggest adding a small amount of salt to the water to stave off mold.
The water seals the butter from the air and protects it from going rancid.
The dish stays neat and tidy.
This is the butter dish we use in winter - a saucer with a custard bowl inverted overtop. The butter stays too hard, even at room temperature, to warrant using the French butter dish.