Molten tin casting is Finland’s traditional New Year fortune-telling practice of melting metal and reading its shape.
A small piece of tin was traditionally melted in a ladle over a flame and then poured into cold water. The resulting solid shape was examined for symbolic forms, with people interpreting the outline as a prediction or sign for the coming year. Shadows cast by the shape could also be used in some versions of the practice.
The custom is associated with Finnish New Year celebrations and is related to older European forms of metal casting. Interpretations were informal and varied: one person might see a ship, animal, or object while another saw something entirely different.
Safety and environmental concerns have led to alternatives in modern celebrations. Some communities use wax or other safer materials instead of traditional lead-containing products. The practice is therefore best understood as folk divination, not a scientific forecasting method.