Whenever officials came around to check for any illegal distillation, Helen would convince them she was simply preparing to make bread. After it became possible to get an official license in , John applied and received a license in , and thus went legit.
When John died in is sometimes mentioned as well , his son Lewis Cumming took over. Lewis in turn was succeeded by his wife Elizabeth in Elizabeth rebuilt the distillery in , leasing additional land in order to expand the business. The old stills were sold to William Grant, who was looking for stills for his Glenfiddich distillery. By , Cardow was being sold as Single Malt whisky in London, leading to quite the interest in the distillery from investors wanting to take over the company.
Elizabeth always refused, wishing to keep the distillery in the family. Elizabeth unfortunately passed away unexpectedly the year after. The distillery also was upgraded, receiving a second pair of stills, a larger mash tun, and an enlarged tun room which would ensure additional washbacks could be put in. The distillery was closed between and when World War I saw restrictions imposed on barley usage, but it resumed production in October In , John Cummings retires from the board, with his son Ronald Cumming replacing him.
Between and the distillery is largely rebuilt and extended, with a third pair of stills added, and the whisky is relaunched as a single malt. All stills were switched to steam heating in , and in , the brand name was officially changed to Cardhu. A visitor centre was opened in the same year. The distillery is nowadays owned by Diageo, which is a continuation of United Distillers, who took over SMD through mergers.
Cardhu is the 6th best selling Single Malt whisky in the world and is especially popular in Southern Europe mostly Spain. To cope with rising demand, in , Diageo took the step of silently switching Cardhu from a Single Malt meaning all whisky is produced at a single distillery to a vatted malt which contains several malt whiskies from different distilleries , in virtually identical bottles. The single malt and vatted malt whisky next to one another. However, there is quite an extensive range for a Diageo distillery at least available: