It marks the first time such an extensive private whisky collection has been available for sale through an online e-commerce store.
Founded in 2005, Cask88 helps its clients purchase world-class whisky that has been previously exclusive to distillery owners and insiders.
Included in the collection is an expansive selection of bottles from "silent distilleries" so-called because they no longer distill their once-prized spirits.
Over 40 bottles from the Port Ellen and Brora Distilleries, both of which have been shut since 1983, are available for sale.
Other notable distilleries represented in the collection include Macallan, Bowmore, Glenlivet and Highland Park.
Patrick Costello, director of Cask 88, said: "This collection is a rare window into the past, offering the chance to taste whisky that has formed the backbone of Scottish Whisky today.
"It’s with great pride that we can offer the opportunity to experience other eras of whisky including releases from distilleries that have now fallen silent."