It's 6 am and the temperature is below freezing as I approach Oldroyd's Farm in Carlton, West Yorkshire. The moon hangs in a dark sky and every surface is covered in delightful sparkling frost crystals. I have arrived before dawn to photograph the famous, forced, fuchsia pink rhubarb being picked in darkened sheds.
Carlton is a village near Wakefield triangulates with Leeds and Bradford to form the Rhubarb Triangle. The Rhubarb Triangle is the heart of the British rhubarb industry. The climate in the triangle provide perfect conditions for growing rhubarb which needs plenty of water, cold weather and nitrogen rich soil.
Forced rhubarb begins life as cuttings taken from mature crowns between two and four years before it is harvested for eating. When large and strong enough the young rhubarb crowns are planted out in fields to grow in rich, well drained soil until it is ready to be transferred to the forcing sheds. Rhubarb needs lots of nitrogen to grow well and traditionally the fields were fertilized with shoddy a bi-product of the wool industry high in nitrogen and still used today together with plenty of organic matter.
Forced rhubarb is lifted from the ground in December after it has received the correct number of 'frost units'. Exposure to frost makes the rhubarb crown break its winter dormancy. Sub zero temperatures stimulate the conversion of starch stored in the rhubarb to glucose and provides energy for the rhubarb sticks or 'petioles' to grow.
Growth in the darkened sheds occurs because the plants have enough readily available energy to produce stems and leaves. Note the leaves are yellow rather than green because of the lack of daylight. Forced rhubarb also needs warmth and the sheds are heated by propane fuelled blowers. In the past coal was supplied from the nearby collieries to fuel stoves in the sheds.
Light discolours and toughens rhubarb sticks and traditionally rhubarb was harvested by candlelight. These days low electric lights are mostly used.
The pickers this year are mainly from Bulgaria and spend many hours working steadily, backs bent over the lines of rhubarb crowns. They gather armfuls of the beautiful magenta stalks cradling them like babies before placing in boxes ready for grading and packing. Yorkshire rhubarb is sold to supermarkets and the best restaurants in the UK.
Dutch forced rhubarb is also available in the shops but there is a difference. Dutch rhubarb is grown in a warmer climate and is not subjected to sub zero temperatures. The flavour and texture is therefore different. So buy Yorkshire rhubarb if you can.
One of my favourite ways to cook forced rhubarb is to poach it gently with a little grated ginger and a sprinkle of sugar to serve with a light version of panna cotta made with a mixture of buttermilk and cream. Soon the tender shoots and lacy leaves of sweet cicely will be appearing along the hedgerows and riverbanks in Yorkshire where it grows profusely. Sweet cicely can be added to rhubarb to enhance its flavour and add sweetness reducing the amount of added sugar required to make it palatable.This year I thought I would experiment and make some delicate tartlets.
When we are in the wilds of Northern Finland we eat a lot of rhubarb as it grow well in Scandinavian countries and this made me think of adding a little rye flour to the biscuit thin shortcrust pastry I normally make. Adding rye gave the pastry a nutty texture. It was still very crisp and buttery. I liked it.
Beneath the poached rhubarb I made a layer of hazelnut cream flavoured with a dash of Cointreau.
Rhubarb and hazelnut tartlets with crisp rye pastry
Makes 6
For the pastry
75g plain white flour
25g rye flour
pinch of salt
60g unsalted butter, chilled and cut into 2cm cubes
2-3 tbsp chilled water
For the filling
50g hazelnuts
30g plain flour
30g soft brown sugar
2 tbsp half fat cream cheese
1 tbsp Greek yoghurt
1/2 tsp vanilla essence
2 tsp Cointreau
6 rhubarb sticks, cut into 3cm lengths
30 caster sugar
vanilla sugar for dusting
fresh angelica leaves to garnish (optional)
Begin by making the pastry. Place the white and rye flours into the bowl of a food processor, add salt and the cold butter. Process for 20 seconds or until the mixture resembles fine breadcrumbs. Start to run the food processor and gradually add the water. Continue to process until the pastry forms a ball. This should take about 30 seconds. Remove the pastry and chill for 15 minutes.
While the pastry is chilling, place the rhubarb in a saucepan. Add 100 mls of water and the caster sugar. Bring the rhubarb to a simmer and cook for 3 minutes. It should remain firm. Remove the rhubarb from the pan with a slotted spoon and set aside. Continue to simmer the rhubarb's cooking juice until it becomes a syrup. We will use this to drizzle over the tartlets before serving.
Preheat the oven to 200°C, gas mark 6. Grease 6 tartlets tins measuring approximately 10cm in diameter.
Remove the pastry from the fridge. Dust a work surface with flour and roll out the pastry as thinly as you dare (3mm). Cut six discs of pastry and line the tarlet tin. Prick the base of each tartlet with a fork and place a disc of scrunched foil inside the pastry case and fill with baking beans. Cook the tartlets for 10 minutes, remove from the oven. Take out the baking beans and scrunched foil from the tartlets and return them to the oven to cook for a further 10 minutes. Remove and allow to cool.
Scatter the hazelnuts on a baking tray and roast in the oven for 10 minutes. Place the roasted hazelnuts in a tea towel and rub off their skins. Blitz the hazelnuts in a food processor or a pestle and mortar. Combine the hazelnuts with the plain flour, soft brown sugar, cream cheese and yoghurt. Add the vanilla essence and Cointreau and mix to a paste.
Spread the base of tartlet case with a generous dessertspoon of hazelnut paste and top with sticks of rhubarb. Bake the rhubarb tartlets for 20 minutes until the pastry is golden brown. Remove from the oven and brush each tartlet with the reduced rhubarb syrup. Dust with vanilla sugar and if you have any new shoots of angelica in the garden chop them up as a garnish.
