Lime and lime leaf marmalade

Until recently, my only experience of lime leaves was of the dried variety, that come crammed into little spice boxes in major supermarkets, often with a hefty price tag attached for the privilege of acquiring the exoticism conferred by the words 'Kaffir limes'. I'd throw these fragile, desiccated morsels, rather like crisp, curled bay leaves, into a heady mix of coconut milk, lemongrass, ginger and shallots, every time hoping that they'd impart the lusciously fragrant aroma implied by their limey affinity, and every time finding myself disappointed, completely unable to notice any difference whatsoever. I tried adding more, but to no avail. Even sniffing deeply at the box or jar, I'd notice very little olfactory impact at all.

Then recently, I finally opened a packet of lime leaf tea I bought in a market in Cambodia last summer. Straight away I was hit by the astringent aroma, sharp and crisp, like a muskier version of a fresh lime. Brewing the leaves in boiling water, I marvelled at the pale jade colour of the resulting tea, and its feisty citrus flavour, reminiscent of ginger tea in its peppery, citrussy heat. This, I suddenly realised, was the real thing. This was how lime leaves should smell and taste: a deep, earthy yet vibrant aroma, like crossing potpourri with a fresh citrus fruit. 

Still finding myself with a huge crate of Brazilian limes (despite my best endeavours in the way of gin and tonics, cheesecakes, curries and many bowls of fresh papaya, I still have about twenty left), I fortuitously caught sight of Nigel Slater's recent recipe in the Guardian for lime and lime leaf marmalade. As it used a whole nine limes, this seemed the perfect way to both use up some of my lime stash, and indulge my deep love of preserving. 

Though I don't have as much time as I'd like to devote to the stirring of vats of sugary confections, preserving is one of my absolute favourite cooking tasks. I love the transformation of bright, fresh ingredients into something more muted, subtle, possessing a sweet and aromatic flavour of its own. I love the frugality and home economics of the activity, capturing something of the delicious seasonal fruit to eat long after the original product has disappeared (yes, amazingly, there are still some fruits that aren't available in this country year-round: gooseberries, rhubarb, blackcurrants, quinces, to name a few - essentially, all of my favourites, because I'm a masochist like that). 

I love that I can put a few slices of homemade sourdough or soda bread into the toaster in the morning, and, while the smell of burnished bread wafts through the kitchen, peer into my jam cupboard and find myself with an array of delicious homemade preserves to choose from: fig jam, apple jam, quince jelly, and rhubarb and vanilla jam are just some of the current inhabitants of the cupboard. I never have to buy jam; why would I, when ladling a generous spoonful of the homemade version onto steaming toast is so infinitely more rewarding? I also love that each and every jar has come out of a mundane need to 'use something up' yet has produced a result that is infinitely more than convenience. 

The rhubarb, for example, was the woody, sour, summer kind. Five bags of it had been sitting in the freezer, when last November I decided to clear them out in one fell swoop, simmering them in a pan with sugar and a vanilla pod to make the most ridiculously gorgeous pink jam, far more wonderful than I'd ever have expected from beholding those thick, green chunks of the original vegetable.

The apple and blackberry jam, too, notable for it cost me absolutely nothing: the blackberries were foraged from hedgerows in the Yorkshire dales, the apples were windfalls from the tree overhanging our garden in Cambridge, and the sugar and jars were already sitting patiently in the cupboard.

The fig jam I am most proud of, for it arose when I came home from holiday to find one of Mum's colleagues had given her a huge tray of figs from his garden, yet she'd allowed them to almost rot, sitting in the fruit bowl. They were far too far gone to be edible, soft and squishy with fruit flies hovering eagerly around in droves, but I managed to rescue them with the aid of a bag of jam sugar, transforming them into the most incredible jam, a deep khaki green, flecked with crunchy seeds and chewy pieces of fig flesh, and possessing a rich, caramelly flavour. I only made a few jars, but with every mouthful I feel proud of myself for rescuing those sad fruits - true testament to both the transformative and economical power of preserving.

Preserving may not be as trendy these days as the homely putting together of a Victoria sponge in a kitchen decked with bunting while wearing a Cath Kidston apron and using a Mason Cash mixing bowl, or the frivolous piping of buttercream onto a fussy cupcake, but for me it has an honesty and an integrity greater than almost any other kitchen pursuit. There is a quiet dignity in a homemade jar of jam or marmalade, adorned with a slightly wonky handwritten label. It speaks of promise and of patience. 

Patience was definitely the keyword for my marmalade adventure. Now that I am a PhD student, my weekends have acquired something of a sacred quality. I try, as many PhD students are advised, to treat my research undertaking as a full-time job, working nine to five on campus during the week then taking the weekends off. By and large, it works well (except I won't lie, it's more like ten til five. But I cram a lot of intense work into those hours, so I think it's okay). Even then, I usually have at least something I can't escape doing at the weekends, so I try and make the remaining hours of leisure time count.

Last weekend, those hours were spent extracting the juice from nine limes, then using a teaspoon to scrape every last fragment of pith and membrane out of the shells of said limes. There are three things I would advise at this stage. Firstly, if, like me, you have a nasty habit of biting the skin around your fingers, this is going to hurt a LOT. Secondly, don't use a pretty Whittards teaspoon with a pleasantly decorated plastic handle, because the acid from the limes will melt the pattern into something veritably Dali-esque. Thirdly, don't be in a rush. This is not something to be rushed. 

Oh, and one more thing - you can skip the gym for the weekend if you do this. Purging eighteen lime shells of their innards is surprisingly taxing on the upper arm muscles.

The fun doesn't end there. You then need to shred the lime peel. Nigel Slater was kind enough to anticipate that by this stage, the last thing you probably want to do is painstakingly slice the peel into slivers, so he offers the alternative of chucking it all in the food processor. While I think hand-slicing it would give a more attractive final result, with delicate tendrils of peel suspended in the golden sugary liquid, I probably would have burst into frustrated tears had I decided to attempt this. Instead, it was made light work of in seconds by those spinning electronic blades, and I could sit down for a minute. I had juiced a couple of Meyer lemons for a lemon tart that day, and by some presence of mind had saved the skins, so they went in there too - Meyer lemons have a gorgeous floral fragrance that I thought would be fabulous with the limes and lime leaves. The result of the ferocious blitzing was a beautiful speckled medley of green and yellow shreds. 

After that, everything is fairly simple. You bring the lime juice to the boil with some water, add the peel, then put the pulp from the limes into a muslin bag and suspend it in the mixture, boiling it for an hour or so. Then you add the sugar and lime leaves.

This is part two of my lime leaf revelation. 

Three words: buy them frozen.

I was vaguely aware you could get frozen lime leaves in Chinese supermarkets, but I'd never remembered while there to have a look. I was delighted to find a large tub of frozen leaves in the Chinese supermarket just down the road (my house is excellently located in York for two reasons: one, it's opposite the gym; two, it's about ten minutes from a brilliant Middle Eastern and a Chinese supermarket), for the princely sum of £1.60. There must be at least a hundred leaves in it, so it's ridiculously good value for money.

Comparing frozen lime leaves with dried is like comparing fresh basil with dried: there is simply no contest. The leaves, added to the bubbling syrupy vat of citrussy marmalade, imparting the most incredible fragrance to the liquid and to my house. It's hard to describe the smell of fresh (well, frozen, but once thawed they're as fresh as you'll get outside Thailand) lime leaves, but suffice to say they possess all the positive attributes of a fresh lime - zesty, zingy, citrussy - plus something extra in the form of their aromatic fragrance. 

This marmalade makes your house smell wonderful, like a sweet shop: warm, spicy, cosseting. It turns a beautiful amber colour, flecked with pale shards of lime peel that soften in their sugary bath so that you can crush them easily with your fingertips. The lime leaves work beautifully to consolidate all that fresh lime flavour, adding a little delicate perfume too. 

Ladling the glossy, golden mixture into jars, I suddenly didn't mind so much that I'd spent my weekend in agonising pain, hands smothered in acid, teaspoons melting, millions of sticky, sugary utensils waiting in the sink to be washed. Because I'll get to spend my next precious weekend kicking back, relaxing, and eating doorstop slices of dark soda bread spread thickly with this beautiful fragrant preserve. 

It's hard to describe the complex flavour of this marmalade; it's fresh and citrussy, yet also has an amazing deep, fragrant tang to it from the lime leaves. It's a beautiful golden colour - not an artificial green, as you often find in inferior commercial lime marmalade - and it isn't too sweet; there's just enough sugar to bring out the myriad flavours within. It's really best if you just give it a go for yourself and see what I mean.

The marmalade recipe, by Nigel Slater, is here on the Guardian website. I didn't make any changes apart from using the peel of two Meyer lemons as well as the lime peel, instead of the one normal lemon he suggests, as I happened to have some left over and thought their unusual bergamot-esque fragrance would work well in the mix.