Old Rhosdhu is the name that was given to one of the early single malts made at Loch Lomond, but this particular style of malt whisky was discontinued in 2000. 

Loch Lomond has been a highly experimental distillery since its inception in 1966, distilling on a pair of pot stills with rectifying columns attached to their necks - the Lomond still.  Rhosdhu was one of the first spirit styles made at the distillery, with a 1980s 5-year-old probably the first official bottling of the make.  

By the 1990s there had been a few official Old Rhosdhu bottlings including a no-age-statement single malt and two well-regarded 1967 releases towards the end of the decade. The Rhosdhu style was quietly retired soon afterwards. 

In 2007, after the installation of a new Coffey still at Loch Lomond (separate from the main complex’s grain facility), the Rhosdhu name was revived for a new spirit made with 100% barley on the Coffey still - a style known at Nikka as Coffey malt.

However, due to Scotch Whisky Association regulations, this spirit has to be classified as grain whisky, and today is sold as Loch Lomond Single Grain, made from 100% malted barley. It's a frankly ridiculous situation that's entirely the fault of the SWA, who specialise in this sort of farcical contradiction in terms, but thankfully the whisky is extremely popular.

Independent bottlings of Old Rhosdhu first began appearing in the 1980s from Cadenhead’s and in the mid-Noughties the First Cask series bottled around a dozen versions of Old Rhosdhu 1979. In the last few years some 1990s vintage casks of Old Rhosdhu have begun appearing from various indie bottlers. Most of these confirm that aged Rhosdhu has an appealing malty, fruity floral style suited to longish ageing in bourbon casks.

A ‘lost’ whisky from a working distillery, Old Rhosdhu is definitely worth seeking out.