This stoneware crock is designed to keep your butter fresh and soft at room temperature.
The lid has a hollow flange where you will pack the butter in. This lid is turned upside down while serving butter, but kept in the base when not.
In the bottom pot you will want to add enough water to form a seal with the butter when the lid is in place.
This design was created before the days of refrigeration to keep butter fresh on the counter for several weeks. Be sure to change your water every few days to ensure the freshness of your butter.