Tea, an expensive import in 19th-century Britain, was frequently adulterated by drying and re-coloring used tea leaves, then mixing them with fresh leaves or other plants. Additives included ferric ferrocyanide (Prussian blue), gypsum, and even sheep's dung to give the tea a desired color and weight. These practices were exposed by chemists and public analysts, revealing the extent of deception in the food trade.

The adulteration of tea, a beloved national drink, became a subject of satire and social commentary in Victorian literature. Poets and cartoonists depicted the 'cow with the iron tail' and other symbols of fraud to critique the dishonest practices of merchants. The theme of false or recycled tea also appears in the works of Dickens and Thackeray, who used such details to build their portraits of a corrupt and hypocritical society.