The Grand Macnish became the fine Scotch Whisky that it is today because of a belief held by Robert McNish back in 1863. Being a hard-headed Scot, he set about concocting a lighter whisky which would have a distinctive appearance. After much sampling, a recipe was found using over 40 single whiskies. The percentage of each used varied according to weight, flavour and aroma, the resultant whisky being much lighter than straight malt, although retaining the exquisite flavour of the finest Highland Whiskies.
In 1887 he was joined in the firm by his two sons, John and George. Trade was expanding and the original store in York Street, Glasgow, where Robert had sold China and Indian Tea, Virginia Tobacco and Scotch Whisky, was found too small hence new premises were opened at 92 Dunlop Street. The laying down of large stocks of maturing whisky was a costly affair and to finance this operation the McNish family decided in 1908 to form their activities into a limited company.

In 1904 Robert McNish died and John, who had a flair for salesmanship and entertaining, made his headquarters in London where he was in constant touch with overseas as well as domestic buyers. George, a shrewd canny Scot, stayed in Glasgow and acted as an excellent foil for John. Between 1900 and 1914, sales of Scotch throughout the world increased enormously and the McNish Company, together with many other Scotch Whisky merchants, shared in this prosperity.

When World War I broke out, George, always a military man and holding a commission in Glasgow͢€™s own regiment, the Highland Light Infantry, immediately reported for service in France. He served throughout the War from 1914 to 1918 and, as Colonel George McNish, his meritorious services were tangibly recognised in 1919 when he was awarded the C.B.E. by H.M. King George V.

On his return to civilian life he resumed his activities in the sale of Macnish Scotch, but since he was a man of boundless energy he also interested himself in numerous charities and local government, and became a Deputy Lieutenant of the City of Glasgow as well as a Justice of the Peace. He died in September 1943 at the ripe old age of 77 after 50 years with the company. His brother John died two years later.

1927, after lengthy negotiations, the old McNish Company was purchased by Corby Distilleries but continued to operate independently from Glasgow. In later years Hiram-Walker Group acquired a majority interest in Corby Distilleries and finally in 1991 Grand MacNish was acquired by MacDuff International and since then has gone from strength to strength.