A digestive biscuit is a semi-sweet, wheaten British biscuit made from wheat flour, sugar, and butter or vegetable oil, rolled out, cut into rounds, and baked to a crisp, golden-brown finish. The name comes from an early belief that its bicarbonate of soda content aided digestion, a claim that has since been largely discredited.
The biscuit was first developed in 1839 by two doctors seeking a healthier tea-time biscuit. The now-familiar mass-market recipe was created in 1892 by Alexander Grant for the Scottish bakery McVitie & Price, whose version remains the best-known brand today.
Beyond eating them plain with tea or coffee, digestive biscuits are widely used as a crushed base for cheesecakes and trifles, similar to how graham crackers are used in the United States. They also turn up crushed as a coating for fried snacks in Indian cooking and folded into parfaits and other desserts in Japan.