Some of the world’s rarest Scotch whisky will soon be hitting the auction block as part of the world’s largest private collection -- and could fetch over US$10.5 million.

Specialised whisky auction site Whisky Auctioneer will be selling 3,900 bottles consisting of “the perfect collection”. The spirits were amassed by the late Richard Gooding, a private collector from Colorado.

According to the specialist drinks seller, Gooding spent decades hunting down the perfect whisky collection, regularly traveling to Scotland to search for special bottles at auctions and distilleries.

Whisky Auctioneer founder Iain McClune gives some examples of the selection on sale in the auction’s official news release, “This library of whiskies is filled with very special bottles, each of which has been researched and meticulously examined for condition and authenticity. Amongst the over 3,900 bottles is the largest collection of The Macallan ever to go to auction, including the limited opportunity to acquire the 1926 Valerio Adami and 1926 Fine & Rare 60 Year Old bottlings.”

The two Macallans represent the world’s most expensive whiskies—both of which contain the same liquid drawn from the same sherry cask, which has been dubbed ‘The Holy Grail’ by whisky aficionados.

Other bottles include some of the rarest Springbanks and Bowmores, as well as bottles from various closed distilleries, and more rarities.

“It's incredibly rare that a complete whisky collection of this size and value comes to auction at once, but it is the sheer diversity and comprehensiveness of Mr. Gooding's collection that makes it so intriguing,” Becky Paskin, whisky expert and writer, said in a statement.

The Perfect Collection will go live on Whisky Auctioneer over two separate auctions, from February 7-17 and April 10-20, 2020, respectively.