Rhubarb Day

What the day is

Rhubarb Day is observed on January 23. The January date looks odd for a plant most people associate with early summer, but it is well chosen: midwinter is forced rhubarb season, when the tenderest and sweetest stalks are available.

Rhubarb is botanically a vegetable and is treated as a fruit in the kitchen, which is the first thing everyone learns about it. The second is that only the stalks are edible. The leaves contain high levels of oxalic acid and should never be eaten.

Origin and background

The origin of the observance is not documented. The plant's history is long and mostly medicinal: rhubarb root was cultivated in China for thousands of years as a purgative and traveled west along trade routes as an expensive drug rather than a food.

It became culinary relatively late, and the limiting factor was sugar. Rhubarb is sharply sour, and only when sugar prices fell far enough for ordinary households did it become worth eating. The Victorian period is when it became a British fixture, in crumbles, pies and jams.

Forcing is the practice the January date points to. Crowns are grown outdoors, lifted after frost, and moved into heated dark sheds, where the plant draws on its stored root reserves and produces long pink stalks with pale, sweeter flesh. In the traditional growing area of Yorkshire this is still done by candlelight, because bright light would stop the process. Forced rhubarb is noticeably more delicate than the green-tinged summer crop and needs less sugar.

How to take part

• Buy forced rhubarb if you can find it in January. It is a genuinely different ingredient from summer stalks.
• Do not peel it. The color is in the skin, and forced stalks are tender enough not to need it.
• Roast rather than stew. Cut into lengths, scatter sugar, roast briefly, and the pieces hold their shape instead of collapsing into threads.
• Pair it with orange, ginger, vanilla or rose, all of which suit the sourness better than more sugar does.
• Try it savory. Rhubarb works well against rich or oily meat and fish, much like gooseberry.
• Compost the leaves; do not cook with them.