Vanilla Poached Rhubarb

Rhubarb is a vegetable, not a fruit, despite its habitual place in puddings and its affinity for sweeter companions. It belongs to the polygonaceae family, making it a relative of sorrel.

It is also one of the more reliable crops you can grow in Britain. Rhubarb likes cool conditions and is troubled by remarkably few pests, which is why a large proportion of the national crop comes from the Yorkshire Rhubarb Triangle, where the cold, damp soils suit it particularly well. The forcing method used there was developed in the 1800s, when coal for the sheds came from nearby mines and fertiliser arrived as a by-product of the wool trade. Plants are left to grow for two years without harvesting, storing energy from the sun in their roots as carbohydrate. Frost then sends them into hibernation, converting that stored carbohydrate into glucose — the transformation behind forced rhubarb’s bittersweet character.

A vegetable with a medicinal past

Rhubarb’s extreme tartness is bound up with its reputation as a health food. Tart and sour fruit and vegetables tend to be useful for digestion and cleansing, and rhubarb is no exception. It is high in fibre and has astringent properties, making it effective as both a diuretic and a laxative.

That quality explains why rhubarb was used strictly as medicine for most of its history. Prepared as tinctures, syrups and poultices, it was employed around the world for thousands of years to treat constipation, diarrhoea, gastrointestinal complaints, menstrual disorders, sores and ulcers. In the 5,000 years it has been cultivated, it was not grown for culinary purposes until the 18th century. Before then it was cultivated in Asia and shipped worldwide as a medicine, and the risks and expense of land transport made it extraordinarily costly: ten times the price of cinnamon, four times that of saffron and nearly three times that of opium.

Today it is often classed as a superfood, thanks to its ratio of health benefits to calories — just seven calories per 100 grams. It has also found favour with slimmers who note that it speeds up the metabolism, while its calcium content makes it a fat-free alternative to dairy products for those looking to lower cholesterol.

Cooking it properly

Rhubarb cooked in a saucepan tends to turn stringy and overcooked, however carefully you watch it. Baking it in a low oven is easier and gives better results: it cooks through while staying tender and holding its shape. If you are cooking it after something else — a Sunday roast, say — simply put it into the turned-off oven while you eat. By the time the plates are cleared and the pudding dishes are out, it will be ready.

A little vanilla and lemon balm add a subtle fragrance, though the dish is perfectly good without either.

Serve with ice cream or clotted cream, or use it in a rhubarb bundt cake or as a strudel filling.