You’d never guess that John Cannon, taking long strides down his orchards in the lovely Bourne Valley, in Kent, was approaching his 80th year. The secret of his vitality? ‘Cobnuts,’ he smiles. Well, he would say that. He’s the president of that distinguished body, the Kentish Cobnuts Association.

But I wouldn’t be at all surprised if he weren’t right. Cobnuts are brimful of vitamin E, calcium and other life-enhancing substances. I cannot, from personal experience, go quite as far as Mr Cannon, when he cracks one open, displaying the white, tender curve of the fresh kernel in its brown half-shell, and says: ‘They’re like oysters, aren’t they? Aphrodisiac.’ But half a dozen provide the same nutritional goodness as a slice of steak. I guzzled about 30 as we walked the fields. Milky and sweet, with a crunch like fresh coconut, they are, above all, good to eat.

Now, when I say cobnut, don’t think of the wizened little balls that inhabit hazelnut shells around Christmas. Those, like nearly all the nuts we eat at that season, are kiln-dried and imported. A fresh cobnut, like a seagull’s egg, is one of the few truly seasonal foods that are left in this age of round-the-year strawberries and anytime mange touts.

Cobnuts

Already, however, I’ve sewn unintentional confusion by the mention of hazelnuts. Concentrate for a moment. Cobnuts are a type of hazelnut, as are their first cousins, the more torpedo-shaped filberts (St Philbert’s Day, August 20, is traditionally the first day that the earliest varieties of cobnut can be picked.) Kentish Cob is the most popular variety, although, colloquially, some people use Kentish cobs as a generic term. Clear?

It doesn’t matter. Suffice it to say that cobnuts are all pretty small and variants on spherical. They come in as many as 60 different kinds, not all of which are commercial, from the elegant Imperatrice Eugenie, pretending that the green frills of its husk are a ball gown, to Gunslebert, a Germanically heavy cropper. For sweetness, there’s Butler, discovered by a Mr Butler growing in his American orchard; for size, the aptly named Cannonball, which would have done some damage fired from muskets on the plains of Waterloo; but steer clear of Fertile de Coutard ‘a horrible French nut, impossible to crack’.

Man has been eating hazelnuts since the Stone Age. Nutting the gathering of wild nuts remained one of the joys of the countryside for centuries, celebrated by Thomas Hardy in Under the Greenwood Tree. In his Dictionary, Dr Johnson, curiously, seems not to have known the cobnut as something to eat, but as the champion nut in a game of the same name, played on the basis of conkers. ‘The object of each party,’ notes John Brand in his Observations on the Popular Antiquities of Great Britain, 1849, in terms that would probably not be chosen now, ‘is to crush the nuts of his opponent.’

The cobnut’s zenith of popularity was reached during the Victorian age, when polished mahogany dinner tables were cleared for dessert. Cobnuts then were as much a part of the post-prandial ritual as port. The beautiful blue hills of Kent may have devoted more than 50,000 acres to the orchards that grew them. ‘The golden triangle lay between Tonbridge, Sevenoaks and Maidstone,’ says cobnut grower-cum-Chesterton Humberts estate agent Alexander Hunt. It still does.

After the Second World War, the public turned its back on this home-grown treat. Mechanisation was the vogue in farming, and sloping fields of bushy nut trees didn’t lend themselves to it. When Mr Hunt started out 20 years ago, he was offered an old orchard, solely on the basis that he would pick the nuts. Supermarket shelves were stocked with mechanically harvested nuts from Turkey and California. The home market had collapsed.

Now, the cobnut is finding a niche, with the better supermarkets dedicating shelf space to fresh English nuts until the avalanche of their dried, foreign brethren arrives towards the end of the year. The whole of Mr Hunt’s production, however, is sold direct to the public, through farmer’s markets and the internet. As a result, cobnuts are recolonising the county, the area under commercial cultivation having risen from practically zero to about 400 acres.

At Roughway Farm, Mr Cannon rummages in the green depths of a cobnut tree and extracts a cluster of Cosfords, their thin shells only just covered by a fringed elf’s cap of husk. They are truly ‘a nut for connoisseurs’, of excellent flavour. Then, he pulls a few, whippy shoots off the tree. Even in a dry season, the trees grow quickly and need to be thinned, to let in the light that helps nuts form next year.

Already, the catkins of the next crop are forming. They will blow yellow in the spring. I leave the farm with my pockets bulging with cobnuts, knowing that, at home, I will not be able to tell a White Filbert from a Merveille de Bollwiller. But who cares? They’re all Kentish cobs in the vernacular. And I’ve discovered the elixir of life.

What to do with cobnuts

Fresh cobnuts can be eaten in salads or simply out of their shells. They’re milky, crunchy and sweet. Straight from the tree, they nestle in a husk of green and tan frills, which turn brown after a time, but remain a pretty addition to the fruit bowl but don’t leave them there for too long. Like other fresh foods, they need to be kept in the fridge. Throw away any loose husks, but don’t remove ones that are still green and firmly attached to the nut. A little salt helps preserve them. If you store them correctly, they should keep until Christmas and the New Year. To buy direct, visit www.kentishcobnuts.com

Watercress, sweet  pear, rocket and parmesan salad

Serves 6 as a starter

Ingredients

3 large ripe pears (peeled if you wish)
100g watercress
100g rocket leaves
Juice of 1 lemon
Olive oil
30-40 fresh cobnuts
60g parmesan

Method

Put the washed rocket and watercress in a large bowl. Cut the pears in half, deseed and slice each half into four lengthways. Add them to the bowl. Pour over the lemon juice and a good drizzle of olive oil and season, then toss the ingredients together. Shell the cobnuts and chop them in half lengthways. Place the salad on six small plates and scatter the cobnuts roughly over each serving. Finally, shave the parmesan on top. Serve immediately.

Taken from ‘The Kentish Cobnut Recipe Book’ by Alexander Hunt, £14.99, available in February 2010 through www.kentishcobnuts.com