How Britain's biggest brewery produces 3 million pints of beer a day in Burton upon Trent. How four basic ingredients – water, malted barley, hops and yeast – are manipulated to make dark, heavy ales; light, fragrant lagers; and everything in between. How the hard water of Burton – perfect for brewing flavourful stouts and porters – and its position on the canal network made it the centre of brewing in 19th-century Britain. How beer-making turned from a predominantly female cottage industry to an industrialised process dominated by men.