James Mackell Montgomery had been a brewer in Monkwearmouth in Sunderland from the 1860s before moving to Haddington in 1881 to take on the tenancy of the Sidegate Brewery from James Richardson. He acquired the brewery the following year and commissioned additions to the buildings between 1893 and 1894 from noted Edinburgh brewery architect Peter Lyle Barclay Henderson.
In 1896 he sold his business to the newly formed Haddington Brewery Co Ltd, becoming one of the directors until 1897.
Active: 1881 - 1897
The Sidegate Brewery was arranged around a courtyard and consisted of a brewery, malt kiln, granaries, cellars, steam engine house, stable, guano house, and garden, and has having a 12 quarter maltings.
Much of the complex has since been converted into private housing in what is now known as Brewery Close.