Cold butter is never fun to spread. Our marble butter keeper - also known as a butter bell -solves that problem. Marble naturally keeps butter cool, without refrigeration, and at a spreadable consistency. Simply fill the base of the crock with cold water, fill the butter holder with softened butter, and invert the holder into the crock. Butter will stay fresh for 30 days outside of your refrigerator. Holds 1/2 cup (one stick) of butter.