This ingredient is especially prized because of its unusual season - January to March - when there are few new British ingredients to grab our attention.
The crop is predominantly grown in forcing sheds in the ‘Rhubarb Triangle’, a small area of nine square miles in West Yorkshire and was granted Protected Designation of Origin (PDO) status in 2010.
It is highly regarded by chefs and caterers on account of its complex flavour, low acidity, health benefits and dazzling colour.
As most people know, the rhubarb is grown without light ('forced') in dark muggy sheds. "It's very labour intensive - you wouldn't believe it," explains grower Jonathan Hick, who suppliers wholesaler P & I in the Market.
I've visited these sheds. The atmosphere is warm, humid and sonically bizarre, marked by the squelch of boots in the soil and the snap, snap, snap of the picking process as the stalks are tugged from the root.
In the last few years, growers have benefitted from the new trend for artisanal spirits. "In the Northern cities the gin houses are flourishing," says Hick. Gin and vodka makers are buying Grade II rhubarb (which is trickier to sell) to flavour their creations, such as the brand modelled here on Instagram by mi5tyswallows.
- Forced rhubarb requires sub-zero temperatures (measured in 'cold units') to trigger vernalisation of the roots (the signal to start growing once again). But milder winters mean the season is starting later. (“Nature has just turned on its head unfortunately,” says Janet Oldroyd Hulme of leading grower E Oldroyd and Sons. "In my time [the season has shifted] a week to a fortnight later .. three weeks over a generation," adds Hick.)
- The season for Yorkshire forced rhubarb now runs roughly from mid January to March. This year has seen suitable weather conditions and a good crop.
- Growers plant range of different varieties to stagger the crop. Timperley Early, for example, requires fewer cold units - so is typically the first crop. But it has a lower yield than later varieties such as Queen Victoria. (Find out more on this subject here).
- Botanically speaking, the pink 'stems' are actually the petioles of the plant.
- Forced rhubarb has proven health benefits. The petioles contain ideal levels of oxalic acid, which helps to cleanse and detoxify the body, and high concentrations of polyphenols - special molecules in plants with powerful antioxidant properties. It also boasts a lower acidity than the outdoor crop.
- The forcing process was first discovered in 1817 in Chelsea Physic Garden. The plant, which originates from Siberia, was previously used as a medicine and its use has been traced back to 2700 B.C.
- Growers will also cultivate rhubarb outdoors so they can supply through the year. Oldroyd Hulme's father finished harvesting outdoor rhubarb in August. Now, because of milder weather, the family are harvesting throughout October.
- The Yorkshire growers face some competition from the Netherlands, which has claimed a slice of the trade.
Growing and harvesting
Forced rhubarb begins life with two to three years in the open fields. This is so the plant can build up its root system and stores of energy, which it will have to entirely rely upon when moved into the forcing sheds. The pictures below are from growers E Oldroyd and Sons and Alan Dalton respectively.
Up to 15,000 roots are packed into each shed. “Some of the roots systems in Yorkshire can take two men to lift them,” chuckles Oldroyd Hulme.
The growers then simulate the arrival of spring. “Everything we do then is a trick,” explains Oldroyd Hulme. The sheds are heated, for example. Sprinklers are also used. “Spring rain helps the plant grow and wakes it up,” she says.
Light is excluded from the sheds, so growers pick by candlelight. (Small extra corner lights are also used nowadays due to health and safety).
The rhubarb is taken back to the pack house for grading once harvested. After four weeks the root is exhausted and as it is unsuitable for further cropping it is composted to add organic matter to the fields.
In the market
“There’s an awful lot of growers up there,” explains Eddie Barrett at H G Walker, a wholesaler on the market. “And they are all good.”
This quality product is sold by several wholesalers including H G Walker, Gilgrove and P & I. The product is typically sold in 6.35 kilo / 14 lb boxes. The picture below from Hick shows vintage tickets from back in the day.
This ingredient is irresistible for chefs - brightening up any plate. At Quo Vadis in London, chef patron Jeremy Lee serves the ingredient with mackerel, beetroot, horseradish and blood orange. He chops the rhubarb into 1 cm cubes then covers in a boiling pickling liquor made with cider vinegar, sugar, salt and spices – peppercorns, cloves and some ginger. This is all then transferred onto a tin foil lined baking tray and baked until soft. He then allows the rhubarb to cool on the baking tray without moving it, so that the individual cubes don’t turn mushy.
This is from Jesse Dunford Wood, with rose petal ice cream and shortbread.
And product developer Tassy Goodall is using dehydrated rhubarb to decorate a white chocolate cake.
Oldroyd Hulme says some butchers in Yorkshire use rhubarb in speciality sausages. "Rhubarb goes very well with anything with a high fat content, such as pork or oily fish," she says. You can find more inspiration on cooking forced rhubarb in these articles from The Telegraph, The Guardian and Jamie Oliver.
Oldroyd Hulme is positive about future demand, as more people discover the health benefits of the crop.
On the other hand, she is concerned about the milder winters. “What are we going to do about lack of frost?” adds Oldroyd Hulme. “Are we going to have to start chilling the roots?" This will add costs to what is already a very expensive process.
With energy costs spiking in recent years, the cost of heating the sheds is another challenge. Wind turbines, solar panels or anaerobic digesters are possible options.
“My father would be very worried now if he was here - I know he would – but he loved a challenge,” says Janet. “It’s like there are problems thrown at each generation to solve.”