Bidders are readying their paddles and their palates on Wednesday for the auction of what is believed to be the oldest bottle of whisky in existence.

The 400 ml bottle of Glenavon whisky is expected to draw between £5,000 and £10,000 (about $11,000 to $22,000 Cdn) at Bonhams & Butterfields auction house in London. Broken down, that works out to about $665 per shot.

Researchers have been unable to pinpoint the whisky's precise bottling date, but based on the label's markings, believe it was produced before 1901.

A Northern Ireland woman is selling the bottle of pale gold whisky, which has been in her family for three generations. She said with the passing of time, family members became reluctant to break the green bottle's seal.

Richard Harvey, an expert with the auction house, said the whisky has likely retained its quality and taste given that the alcohol matures in the cask, not in the bottle.