Forced rhubarb

Categories: Product of the week

A beautifully bright and highly seasonal cultivated fruit

“I think forced rhubarb is the most beautiful of ingredients. It is this wonderful bright pink colour, which it gives to any dish that you use it in. The leaves are beautiful, too—almost fluorescent green,” says Lesley Holdship, Borough Market demonstration chef. “I also love the fact that it is truly seasonal. It’s only available from January until March and for me, is a sign of spring and the flavours to come.”

‘Forcing’ rhubarb is the practice of covering the young stems with a container to prevent any light from reaching the plant. This ‘forces’ the fruit to develop earlier, in search of the light. It also results in a softer texture, as the photosynthesis that happens when the plant is exposed to light makes the plant fibres tougher. The best forced rhubarb comes from the ‘Yorkshire triangle’.

“In terms of the difference between this and field rhubarb, the most obvious thing is its vibrancy of colour,” Lesley explains. “I would also say it is a lot more delicate in flavour. That astringency is still there, but without the harsh edge you can get with rhubarb grown in normal conditions. It is also slightly sweeter and definitely softer, with a more delicate structure. You have to treat it quite gently.” While the traditional way of cooking rhubarb is simmering it in a light sugar syrup, Lesley wouldn’t recommend this for forced rhubarb—“It would fall apart too easily.” Instead, she likes to bake it in the oven, sprinkled with sugar and covered with foil, which will help the stems keep their shape. “I bake it for 15 to 20 minutes at 180C. Because they are not leaching flavour, you get more nuance.”

An old-fashioned custard tart
The baked rhubarb can be eaten as it is or add your choice of aromatics before baking and use it as the basis of a compote—which Lesley suggests enjoying with an old-fashioned custard tart to really get the best of this seasonal treat. “The acerbity of the rhubarb and the beautiful creaminess of the custard work well together,” she says with a smile. “For the tart, I would choose sweet pastry because when it bakes it goes lovely and crisp, and the custard is not incredibly sweet.” Blind bake the pastry case and make the custard with cream and eggs—“mainly the egg yolk. This way you get a lovely gentle custard; egg whites can make the custard a bit firm. I also sweeten it up a bit with a little caster sugar.” Whisk the mixture and pour it into the pastry case, then bake on a really low heat—about 140C, for about 30-40 minutes.

“Open the oven occasionally and give it a poke. When it’s just starting to wobble, it’s ready. If you leave it in for too long the egg will soufflé and the custard will crack.” Serve a slice of the tart drizzled with the baked forced rhubarb compote and you’re in for a real treat. “You get this lovely pale coloured custard with the amazing pink of the rhubarb. It is an amazing dish. If you want to try something a bit more contemporary, coconut goes beautifully with rhubarb. Just mix in coconut milk with the eggs.”

Another use Lesley has for forced rhubarb is a little more unusual. “It is a wonderful flavouring for gin or vodka,” she reveals. “It produces a really delicious drink with this incredible pink colour. I make it a lot for presents and the recipients are always happy.” Our chef starts by chopping a kilo of rhubarb into rough cubes and putting it in a jar with 400g caster sugar. Leave it for a couple of days to allow it to macerate, then add a bottle of gin or vodka and leave for another four weeks. “It has something of the feel of a liqueur,” Lesley says in a tone that speaks of happy evenings sipping rhubarb gin. “You can also use the leftover rhubarb as a boozy compote. It would make a wonderful base for an adult dessert.”