A bit of butter mold history... Butter molds were first used centuries ago in northern Europe. Today, most of the oldest molds to found in museums date to the mid-18th century Europe and North America. In the 19th century, dairies became commercial and butter - as well as the wooden butter mold - was widely mass-produced. Antique molds of the late 19th and early 20th century are often found in personal collections. Antique American butter molds have, in the past forty years, become popular Americana collectibles and greatly increased in value. Such molds are - due to their condition - best used as decorative accent pieces.
It is as rare to find modern butter molds as it is to find someone who knows how to use them. Instructions for use of a modern butter mold: 1 - Soak the mold in ice water for 30 minuutes and -if convenient - refrigerate the mold for 30 minutes more. This helps to keep the butter from sticking in the mold. 2 - Rinse the mold with cold water and fill it with softened butter. 3 - Smooth the surface with a spatula and cover with plastic wrap. 4- Chill for 2 hours or more.
5 - To unmold the butter, run the tip of a knife around the outside edge to loosen it.
Cleaning wooden molds: Use hot water, mild soap, and a brush to loosen residue - but do not soak the mold in water.
Reconditioning molds: Mineral oil may be used to recondition a mold and prevent drying and cracking. Vegetable oil should not be used.
Food professional teacher, Alice Ross, writes of butter making and molding (Hearth-to-Hearth, October 2000):
If you want to try it yourself, the trick in a successful casting is to first soak and chill the mold.
Then, after packing the butter in, refrigerate until firm, and then pop out into a plate.
If you want to make your own butter to match the handsome form, all you need is fresh whipping cream.
Whisk or beat past the whipped cream stage until the butterfat forms firm yellow lumps and separates
from the remaining buttermilk. (Save the buttermilk: let it sit out at room temperature overnight
to culture, and either drink it or use it in cooking.) Paddle and press the butter in several washes
of cold water until there are no traces of buttermilk left. Salt if desired.
Pack into soaked and chilled wooden molds, refrigerate to harden and then un-mold."