Numbering only 150 bottles, the half-century old Scotch will launch to Hong Kong travel retail from March 21 and later be unveiled in Singapore, Seoul, Shanghai, Beijing and Taipei.

From June this year, it will be launched in other international duty free and domestic markets. Price is on request.

The whisky is housed in hand-blown crystal glass decanters, designed in the image of Glen Grant’s pot stills and featuring the number 50 in 18-carat gold lettering.

Dennis Malcolm, who filled the cask in 1963 and later became Glen Grant master distiller said: “Maturation cannot be rushed. Like people, casks mature at their own pace. I have protected and cared for this barrel for 50 years, letting it breathe and patiently waiting for the magic and interaction of whisky and wood.”