Oinomancy (or oenomancy or œnomancy) is a form of divination by interpreting the patterns in wine.
Derived from the Greek oinos ('wine') and manteia ('prophecy')
Oinomancy can be traced back from ancient Greece and Rome where wine was poured as a libation to the gods, hoping for a prosperous future. The ancient practice was performed by a priestess known as a Bacchante, and protected by Bacchus, the Roman god of wine.
Oinomancy could be done in various ways:
Spilling out the wine on a cloth or paper and examining the stains
Soaking or boiling a cloth or paper in wine and evaluating the patterns formed on the material
Pouring a wine as an offering during libation and observing its appearance
Studying the sediments formed in a glass or bottle of wine
Studying the physical features of wine such as color and taste
The procedure known as the 'three vases of Artephius' is a divinatory method related to the magic mirror, hydromancy, and oinomancy.
Drinking to someone's health is a modern survival of such old customs.
Deities associated with the practice