It is based on Harviestoun’s award-winning Old Engine Oil. With more than a stylistic nod to the classic Imperial Porters (and Stouts) of the nineteenth century, this deliciously rich, dark, 8% a.b.v. beer is the first ale to be aged in malt whisky casks from a named distillery and, with traceable casks and numbered bottles, the rest with genuine provenance. Ola Dubh will initially be available in three different expressions; the initial release will be of small batches aged in casks formerly used to mature Highland Park 12 Year Old, Highland Park 16 Year Old and Highland Park 30 Year Old. Further variants are planned for the future. Ola Dubh is, in the words of beer afficionado Owen D.L. Barstow: The most interesting new British beer I have tried in years.