London's jam jar revolution

"It's austerity chic," she tells me frankly. "It comes from the days when I cooked in squats and at anti-G8 demos. I like the idea that something associated with poverty is now the height of fashion."

Jars are a thing of beauty, she argues. Simple, elegant, classless. "A lot of mass-produced glasses that you buy are no better than drinking out of jam jars."

As part of a new radical home-making movement taking place in America, foodies are cooking and serving meals in jars, learning to preserve their own produce from gardens and allotments.

"They call it the 'canvolution' or home 'canning'," Rodgers explains. "Which is slightly misleading because it's not about putting food in tin cans. Instead they're reviving an older preservation technique, using fermentation, water baths and glass jars."

To cook their own north London feast, Rodgers and foodie and winemaker Matt Day imported a huge American pressure canner (basically a state-of-the-art pressure cooker) and served potted salmon rillettes, bouillon, truffled macaroni cheese with a dill cucumber and lime and coconut pickle. Dessert was Pruneaux en Armagnac with crème fraîche.

"It felt like your very own picnic," enthused one diner. "Jars are ever so comforting because they make you feel delightfully studenty and bohemian."
Home canning improves the flavour of vegetables and fruit. It's green because you don't need refrigeration, plus you don't waste excess food. And you can layer ingredients so it looks appealing.

The trick, says Rodgers, is to fill jars half with solids, half with liquid. In the canner the water should just cover the jars (if you're not using a pressure canner with a special jar rest, then put newspaper or a tea towel on the bottom). Place on a high heat until pressure starts to build up. Then cook to a lower heat for around 20 minutes.
"Leave jars to cool for 24 hours. You will hear the lids popping. If the lid does not pop, then do not use that jar," she advises.

In the past, the image of bottling had a utilitarian, make-do-and-mend vibe. But the new approach is about fantastic flavours and has a great sense of style.

Rodgers has heard from people baking cupcakes in jars... handy, as they don't get squashed when sent by post.

Day is even looking into canning to launch his own London wine bar. There won't be a chef; everything will be canned, from snacks and simple soups to stews and couscous.

But it's not just food. Jars are a chic way to decorate a room. At florist Scarlet and Violet in Kensal Green, they advocate the wildflower meadow look - bunches of cow parsley and cornflowers displayed in jam jars.

London craft maker and recycler Hannah Bullivant (seedsandstitchesblogspot.com) uses jam jars as everything from shot glasses to pen pots and humane bee traps. She even refashions them as photo frames. "You simply spray the lids your favourite colour and pop your pictures in. Or you can add keepsakes, fabric scraps, pressed flowers."

For Bullivant, the jar has a unique, utilitarian charm. "Reusing jam jars prevents them from being sent to landfill or being melted down and recycled - quite carbon-intensive. Most of all, however, I love that they are free, a big plus in these belt-tightening times. I recently served Sunrise margaritas in them at a party and they went down a storm! I also happen to think they are gorgeous in a 'practical chic' sort of way."

You start to realise there are jam jar tribes. Food bloggers like Gloria at laundryetc.co.uk wax lyrical about the charms of vintage French jam jars over Mason jars or curved Ball jars (imported from the States). On canning forums they have heated arguments about classic twist-off lids over French lightning clip jars.

Rodgers has a fetish for modernist Weck jars from Lakeland. "Branston Pickle jars are my favourite," laughs Bullivant. "I love their shape and the lip on the jar means they are perfect to drink from! Bonne Maman jars are another favourite with their pretty red and white chequered lids - good for storing buttons in."

If you can't see yourself going native and buying a home canner, then Rodgers is launching her own slightly louche boozy jams - made by pressure canning - with champagne, sloe gin and calvados in May. Dubbed "Mauvais Maman" ("Bad Mother"), you'll be able to buy them at the underground farmers' markets she holds at her house.

The range is inspired by her squat background - but with a new spirit of enterprise. "I really want to encourage DIY punk, start-up businesses. And jars go with the whole eco aesthetic."

Kerstin Rodgers, aka MsMarmitelover, is chef-patronne of The Underground Restaurant, based at her house in Kilburn (marmitelover. blogspot.com). Her first recipe book, Supper Club, is published by Collins, £25.