Poire Williams is the name for eau de vie made from the Williams pear (also called Bartlett) in France and Switzerland. It is generally served chilled as an after-dinner drink. Some producers of Poire Williams include an entire pear inside each bottle, called prisonnière. This is achieved by attaching the bottle to a budding pear tree so that the pear will grow inside it.
Commercial brands of Poire Williams include Williamine, produced in Switzerland by Distillerie Louis Morand and protected as an AOP.