This firm, based at the Sandyford Stone Brewery, was made a limited company in 1897. In 1899 Robert Deuchar bought Pattison's Duddingston Brewery near Edinburgh, and a year later, Simson & McPherson Ltd. The latter was originally based at James Simson's brewery in Melrose, from 1839, but in 1864 opened St Mary's Brewery in Edinburgh. In 1896 Simson's existing connections in the north east were strengthened by a merger with James E McPherson & Co, whiskey blenders.
Brewing gradually ceased at Edinburgh, Melrose and later Sandyford, and the buildings were used for bottling, bonded warehousing and other purposes. Production was concentrated at Duddingston.
Robert Deuchar died in 1904, and his son Farquar Deuchar in 1947, following which the firm passed to trustees who accepted an offer from Newcastle Breweries for the ordinary share capital. In 1959 all except the Scottish assets were fully amalgamated with Newcastle Breweries, and the firm of Robert Deuchar Ltd converted to a private company to dispose of the Scottish interests.