Mackeson Brews an Early Milk Stout

In 1907, Mackeson & Co. of Hythe, Kent, brewed an experimental stout containing lactose. Unlike the sugars normally present in wort, lactose is not fermented by standard brewer’s yeast, so it remains in the finished beer and contributes sweetness and body. Mackeson developed the beer within a longer history of attempts to combine beer with milk-derived ingredients, but its product became the defining early commercial example of milk stout. After trials and test marketing, Mackeson released the beer publicly around 1909 or 1910. Its success established milk stout as a recognizable beer type and encouraged both licensed production and competing brands across Britain. Advertising promoted the beer as nourishing and suitable for consumers beyond the traditional male pub audience, helping milk stout become an important British stout variation during the twentieth century.