Margaret Ainslie was granted the renewal of the licence for the Nairn Brewery in 1898, instead of David Bernard Rose; the brewery was then renamed the St Bernard's Brewery. Margaret's son Robert then traded as Ainslie & Co, until 1903.
Amongst the beers produced at the brewery were Extra Stout and Sparkling Dinner Ale.
The St Bernard's Brewery consisted of a small group of buildings on Mill Road, organised around a central courtyard. The brewery was destroyed by fire in 1903 and most of the ground has since been landscaped.