This is the system of buying wine that is not bottled, commonly practised in Bordeaux.
Buying wine as futures, particularly of the classed growths in Bordeaux, has become increasingly popular in the late 20th and early 21st century.
Cask samples are tasted by buyers and critics, the wines are assessed and scored, and subsequently, the chateaux and brokers offer ‘tranches’ (literally slices) of their wine to merchants in France and abroad.
The consumer pays for the wine and then waits for the wine to be bottled and shipped to their home country. They then must be any duties and taxes to their government if they wish to drink it or remove it from a bonded warehouse.