William was the son of Archibald Mitchell, the founder of nearby Springbank Distillery. In the second half of the 1800s William ran Springbank Distillery in a partnership with his brother John, while the other brothers and sister were active running the old Rieclachan Distillery across the town. The family were not just distillers but also farmers, which was quite a common thing in those days. The growing of barley and production of farmers’ feed (a bi-product from mashing) meant that it made sense to run a distillery as well as being a farmer to keep the cost down. The farming element in the partnership with John didn’t run very smoothly – allegedly the two brothers had a quarrel about sheep – and this saw William leave the family business to start up his own venture, Glengyle Distillery on the corner of Glebe Street and Glengyle Road, just down the road from Springbank.