In 1856, Joshua C. Gray, of Irish decent, founded Gray's Bottling Works in Janesville. J.C. Gray had experience in the industry and was involved in Cottage Tavern which helped him to start the company in Janesville. He brought with him family recipes that were the cornerstone of the company. His original book, which stressed using only the finest ingredients and time-proven techniques, is still in possession and used by the brewery. 

Throughout the generations, the family business has adopted several names. Starting with Gray Bottling Works, it changed to Chas. C. Gray Beverages and then Gray's Beverage Company before adopting the current name of Gray Brewing Company. In the late 1890s, the Gray family discontinued brewing beer to focus solely on soft drinks. This decision was based on the strength of soft drinks sales and the ever-growing temperance movement.

The business is currently operated by fifth-generation Robert (Fred) Gray II. After being founded by Joshua C. Gray, ownership  moved from generation to generation: Charles Gray to Charles Gray II and Margaret Gray to Robert Gray to Robert (Fred) Gray II. Today, Fred's children, Sarah and Jacob Gray, have joined the business to give it a sixth generation. 

Gray's was first located at 52 Locust Street, moving to its second and current location on West Court Street in Janesville in 1959. 

Today, the business continues to honor its forefathers, who had the courage, vision, and ambition to sail across an ocean to follow a dream - a dream that stands today, over 150 years into its sixth generation. Gray Brewing is on e of the nation's oldest family-owned-and-operated beverage companies.