Ava Gardner, Winston Churchill and Mark Twain all understood the importance of a good bottle of whisky.

But even they might balk at the price of a 97-year-old bottle of Macallan to be sold at Sotheby’s in London, which the auction house is estimating could fetch £1.2m.

Already the world’s most valuable whisky – in 2019, a bottle of Macallan 1926 set a £1.5m record – the bottle being auctioned on 18 November is expected to cause particular excitement.

This bottle is estimated to sell for between £750,000 and £1.2m, meaning a single 25ml shot would be worth between £25,000 and £40,000.

The Adami 1926 is the oldest Macallan vintage ever produced, bottled after being aged in sherry casks for six decades.

Only 40 bottles of Macallan 1926 were produced in 1986, but these were not made available for purchase. Instead, offered to Macallan’s top clients, records are broken each time one appears at auction: between 2018 and 2019, the record was broken three times by three of the different variations, Sir Peter Blake, Michael Dillon, and Fine and Rare.

This particular bottle is one of the 12 of Macallan 1926 bottles which in 1993 had their labels designed by the Italian painter Valerio Adami. Its unique selling point is that it is the first to have undergone reconditioning by the Macallan distillery, involving the replacement of the capsule and the cork – and a 1ml liquid sample being taken to test against another 1926 bottle at the Edrington offices in Glasgow.

This one Macallan 1926 Adami bottle is now the foundation for all other 1926 bottles that may undergo testing in the future.

“The Macallan 1926 is the one whisky that every auctioneer wants to sell and every collector wants to own,” said Jonny Fowle, Sotheby’s global head of spirits. “I am extremely excited to bring a bottle to a Sotheby’s auction for the first time since we set the record for this vintage four years ago. Working alongside our friends at the Macallan distillery to recondition and perform clinical analysis on this bottle and liquid has elevated it to an unparalleled status.

“Now, as the bedrock for all Macallan 1926 authenticity and with its condition approved by master whisky maker Kirsteen Campbell, this must surely be the most desirable bottle of whisky ever to come to the market,” he added.

Whether the whisky is ever destined to be drunk – with water, ice or, whisper it, Coke – is unlikely: while one bottle is thought to have been destroyed during the Japanese earthquake of 2011 and another is unaccounted for, just one of the precious 40 bottles has ever knowingly been opened and consumed.