Rhubarb

A vegetable used as a fruit

Botanically, rhubarb is a vegetable — the edible part is a petiole (leaf stalk), not a fruit. The leaves are toxic (oxalic acid poisoning). But culinarily it is treated entirely as a fruit, combined with sugar to balance its extreme acidity. The US Customs Court ruled in 1947 that rhubarb should be classified as a fruit for trade purposes. Its flavour — intensely tart with a distinctive floral quality — is unlike any actual fruit and pairs particularly well with strawberries.

The Yorkshire Triangle

Forced rhubarb is grown in the “Yorkshire Rhubarb Triangle” — a small area between Wakefield, Leeds, and Bradford in West Yorkshire, where a combination of cold winters (to trigger dormancy) and warm forcing sheds produces rhubarb from January onwards. Grown in heated sheds in complete darkness, the stalks grow very rapidly towards the minimal light, producing pale pink, extremely tender stalks. Candlelight harvesting is traditional because even brief exposure to light toughens the stalks. Yorkshire forced rhubarb has Protected Designation of Origin (PDO) status.

Crumble culture

Rhubarb crumble is one of the definitive British puddings — tart rhubarb cooked under a sandy, buttery crumble topping, served hot with custard, cream, or ice cream. The combination of intensely tart, sweet-sour rhubarb with the rich crumble topping and cold cream is considered one of the great examples of British home cooking. The rhubarb and strawberry crumble (combining rhubarb’s tartness with strawberry’s sweetness) is a summer classic.

Historical medicine

Rhubarb root has been used in Chinese and European medicine for thousands of years — as a purgative and for digestive ailments. The plant was traded on the Silk Road as a medicinal commodity before its culinary use in Europe was established. The genus name Rheum is from the Greek for the Volga river, a route by which the root was traded.