Tasseography (also known as tasseomancy or tassology) is a divination or fortune-telling method that interprets patterns in tea leaves, coffee grounds, or wine sediments.
The terms derive from the French word tasse (cup), which in turn derives from the cognate Arabic word tassa, and the Greek suffixes (writing), -logy (study of), and -mancy (divination).
Divination attempts to gain insight into the natural world through intuitive interpretation of synchronistic events.
The first inklings of Western tasseography can be traced to medieval European fortune tellers who developed their readings from splatters of wax, lead, and other molten substances. This evolved into tea-leaf reading in the seventeenth century, a short time after Dutch merchants introduced tea to Europe via trade routes to China.
Scotland, Ireland, Wales and England have produced a number of practitioners and authors on the subject, and English potteries have crafted many elaborate tea cup sets specially designed and decorated to aid in fortune-telling. Cultures of the Middle East that practice divination in this fashion usually use left-over coffee grounds from Turkish coffee/Lebanese coffee/Greek coffee turned over onto a plate.
The Encyclopedia of Occultism & Parapsychology, Fifth Edition, Vol. 2, edited by J. Gordon Melton, notes:
After a cup of tea has been poured, without using a tea strainer, the tea is drunk or poured away. The cup should then be shaken well and any remaining liquid drained off in the saucer. The diviner now looks at the pattern of tea leaves in the cup and allows the imagination to play around [with] the shapes suggested by them. They might look like a letter, a heart shape, or a ring. These shapes are then interpreted intuitively or by means of a fairly standard system of symbolism, such as: snake (enmity or falsehood), spade (good fortune through industry), mountain (journey of hindrance), or house (change, success).