ANYONE WHO has ever cut open those prickly horse-chestnut shells and tried roasting the lustrous mahogany conkers inside will know how bitter they taste. Only the fruits of sweet chestnut trees are edible.
In Yorkshire, sweet chestnuts grow quite widely although they are nowhere near as common as the familiar source of conkers, which despite sharing a name is merely a distant relative.
So it can be a futile exercise foraging for edible chestnuts to roast on a fire or in the oven unless you know where some grow and have the landowner’s blessing.
At this time of year chestnuts are eaten as hot street snacks from brightly glowing braziers. They are added to Christmas stuffings or - with lardons of bacon - used to embellish an otherwise bland dish of Brussels sprouts.
They also provide a good answer to that famous Monty Python question: “What have the Romans ever done for us?”
It was the Romans who first introduced the sweet chestnut to Britain, providing a ready supply of nuts which were ground into flour and cooked like polenta to fill the bellies of the Roman legions.
By the Middle Ages roasted chestnuts had become the popular winter food we know today, and at some point the tree acquired the alternative name of Spanish chestnut, apparently because the fissures which spiral round their often colossal trunks are reminiscent of a flamenco dancer’s swirling skirt.
You can decide for yourself if that’s just the product of an exotic imagination by visiting some of Yorkshire’s famous sweet chestnut trees.
I can think of many lovely examples, such as one in the garden of the author Laurence Sterne at Coxwold; at Newmillerdam near Wakefield; and in the country park at Howell Wood, South Kirkby.
There is a particularly fine tree on the estate of Temple Newsam House to the east of Leeds, said to have been there for at least 350 years and giving it a strong claim to be the oldest tree in Leeds.
Another venerable tree in the grounds of Burton Constable Hall, East Yorkshire, is thought to have been planted around the time of the English Civil War in the 1640s and has an enormous girth measuring almost 25 feet.
Many sweet chestnuts are to be found in the grounds of Studley Royal near Fountains Abbey, such as the one which stands across the road from St Mary’s Church.
The reason these trees were planted around great country houses like Temple Newsam and Studley Royal is that the chestnuts provided food for their herds of deer.
Most of the chestnuts on sale today - the ones that will end up on our Christmas tables - are imported from France, Spain or the Balkans.
They are usually divested of their tough shells and sold in cans or vacuum packs, or processed as chestnut purée.
But some independent fruit shops still manage to find a supply of fresh nuts, and there are few more comforting winter smells than that which comes from them roasting on a coal fire at Christmas.