Nowadays, rhubarb is eaten all over the world, particularly suited to cultivation in temperate climates. In Britain, outdoor rhubarb comes into season naturally from late April, but its indoor ‘forced’ counterpart is available between January and March. What is the difference? The answer is all in the taste: choose the hard, green outdoor variety and you’ll more likely be rewarded with a tart, sharper taste. Choose the rose-pink indoor variety and the tang is softer, sweeter and more fragrant. If you are fortunate to have chosen the crown of rhubarb stalks, don’t forget to check whether it has the official sign of the ‘Rhubarb Triangle’.
The ‘Rhubarb Triangle’? A 9 square-mile area in West Yorkshire, stretching between Wakefield, Rothwell and Morley, the ‘Rhubarb Triangle’ is the world’s most famous producer of forced winter rhubarb. As exposure to sunlight can make the rhubarb stalks green and tough, the forced rhubarb is cultivated in complete darkness, placed in special ‘forcing sheds’ and harvested by candlelight in order to produce a more tender crimson colour. The sheds are specially heated, allowing the stems to turn the carbohydrate into glucose and thus attaining its special sweetness.
The indoor cultivation process was first developed in 1817 and Yorkshire went on to become the world’s biggest producer of early forced rhubarb, cultivating at one point up to 90% of the market. It is thought that in the immediate years following World War II, there were as many as 200 growers operating in the ‘Rhubarb Triangle’ alone, although that figure has gradually declined to only the twelve producers registered today.
Nevertheless, all rhubarb now produced in the Triangle is officially recognised by the European Union as having Protected Designation of Origin status (PDO), along with other protected foodstuffs such as Parma ham, Roquefort cheese and Kalamata olives. The PDO status not only defends Yorkshire forced rhubarb from foreign competition here in the United Kingdom, but also works to promote it as a local and international specialty.
Rhubarb is easy to use in cooking – the fleshy stalks, called petioles, can be incorporated into desserts, or else stewed and eaten alone. Simply cut the rhubarb stems into small pieces (removing the leaves first of all, as these contain high toxicity levels) and heat in a saucepan with a tiny amount of water and a half a teaspoon of sugar to remove the sharpness – you can add more than this depending on how sweet or sharp you want it.
Continue to stew the fruit on a low heat until the rhubarb is soft and thick and soaked in its own pink juices. Serve with cream or a spoonful of natural yoghurt.