Bottled rhubarb

This week Rachel from The Crispy Cook is hosting Weekend Herb Blogging, and I've found an exciting new way of using one of my favourite ingredients.

There are some ingredients so beautiful and exciting that they always put a spring in my step on the journey back from the market to my kitchen. Blood oranges are one; really fresh, glistening mackerel is another; gorgeous jade-green, slightly squat Williams pears, with their promise of fragrant, sweet juice; dark aubergines, plump, glossy and black like beetle eyes. But probably my favourite is rhubarb. Spring rhubarb: bright, almost obscenely pink, poking out of my bag like sticks of rock. It's even better when the leaves are still attached: the contrasting bright green and pink is slightly mesmerising. I just love this vegetable, and am always looking for new ways to use it.

I'm also keen to use it while it's this lovely: as the season goes on, home-grown rhubarb turns tough, dark green, and woody. It needs a lot more sugar, and doesn't have the delicate flavour and colour that works so well in desserts. It's fine hidden under a thick, crumbly pastry crust or a buttery crumble topping, but isn't ideal for topping a snow-white pavlova or mixing into an orange roulade. A couple of weeks ago I bought a kilo of the pink stuff and put it in my freezer, to satisfy any rhubarb cravings that will inevitably arise over the coming months. But when I spied a heap of gorgeous, pale pastel rhubarb at the farmers' market the other day, and realised we have no more space in our freezer at home, I turned to another method of preservation: bottling.

I remembered an article in the Guardian a year or so ago about bottling rhubarb, and needed no further prompting, especially as we have a supply of these beautiful Le Parfait jars at home. I've preserved lemons in them before (great in Moroccan cooking), and they are just too pretty when filled with fruit to sit behind a cupboard door - my preserved lemons sit next to my bed on the windowsill. Ideal if I ever wanted a midnight snack of mouth-puckeringly sour, salty lemon flesh.

I've also bottled fresh apricots before - they are another ingredient I'm absolutely obsessed with when they're in season. I can't get enough of them: they go on my porridge (simmered into a thick, jammy compote with a cinnamon stick and some dates), on tarts, in pies and crumbles, all through the summer until they disappear and I'm left pining for them. They're one of the few fruits that you can't find all year round in England; unlike plums, they aren't imported all year, usually coming from France or further afield in the summer and then disappearing.

The technique for bottling fruit is simple: make a sugar syrup, then pack the fruit in the jars and pour it over. Then you have to vacuum-seal the jars (see below), but that's it. It is, in my opinion, a better method of preservation than jam-making, because the fruit retains its shape and flavour rather than collapsing into an overly sweet sticky mass. That said, I do love making my own jam and chutney as well, but I usually reserve it for things like apples that are in plentiful supply, rather than treasured rhubarb or apricots.

All I did for this was make a sugar syrup, cut the rhubarb into lengths and soak in the syrup overnight, then sterilise the jars (in the oven, though you can also do it in a pan of boiling water or a dishwasher), pack in the rhubarb, bring the syrup to the boil and pour it over. I then vacuum-sealed the jars by closing the lids, but not tightening the metal clasp, placing them in a low oven, and cooking for about 50 minutes before closing them. You can test the vacuum seal on this type of jar by unclasping the metal bit - if the lid stays tightly on, you know it's worked. To be honest, I'm not sure this step is essential - when I bottled apricots I didn't bother, and they were still delicious several months later when I came to eat them.

That's it, really: beautiful jars of gorgeous pink rhubarb, ready to extract and use in desserts and compotes whenever you fancy. I'm going to try and wait before opening my first jar, but we'll see how long that resolution lasts. I already have an exciting rhubarb cake in my mind. And how gorgeous do these jars look? They'll make a fine addition to my bedside windowsill, and a much better potential midnight snack than a preserved lemon...

Bottled rhubarb 

It's difficult to say how many jars this will fill. Your best bet is to sterilise several jars of different sizes, and use a combination to ensure the rhubarb is tightly packed. Mine filled a 1 litre jar and a 500ml jar. See the Guardian article for tips on sterilising and vacuum-sealing jars: this is the method I used, and it worked perfectly, but you can also use kilner jars. You can also double, triple, or halve the quantities as you wish.

1 kilo spring rhubarb, cut into short lengths
400ml water
180g caster sugar
Le Parfait jars (a total of about 1.5l capacity)

Place the sugar and water in a saucepan and bring to the boil. Bubble away for a few minutes, then pour over the rhubarb. Place in the fridge, covered, and leave to soak overnight.

Sterilise your jars by running them through a dishwasher, or washing in hot, soapy water then placing in the oven at 160C for ten minutes, or boiling for 10 minutes in a large pan. Make sure when you take them out of the oven/pan that you put them down on a chopping board or something - if they go on a cold surface they can crack. Sterilise the rubber rings from the jars by pouring boiling water over them.

Remove the rhubarb from the syrup and pack it tightly into the jars. Bring the syrup to the boil, and pour over the rhubarb so it just about covers it. If you don't have quite enough syrup, top up with boiling water fresh from the kettle.

Close the jars and replace the rubber seals but don't clip them down. Put the oven to 110C and place the jars on a baking sheet with some newspaper underneath in case the contents leak in the oven. Put in the oven and leave for 50 minutes. Remove and clip down the metal clips. Alternatively, you can clip the lids down and place the jars in a large pan lined with a teatowel to stop them moving around and breaking. Cover with water and bring to the boil; boil for a few minutes then turn off the heat and let the jars cool in the water.

The next day, unclip the metal. If the lid stays on and doesn't pop up, the seal has worked.