The Spanish or sweet chestnut, Castanea sativa - not to be confused with the ornamental horse-chestnut, Aesculus hippocastanum - is a Mediterranean native whose preference for a hotter, drier climate leads to a disappointing lack of size and succulence in the homegrown crop. This year, however, our own hot, dry summer has produced a particularly plump and prolific crop. Look for windfalls in the prickly carpet of leaves in parks, woodlands and along roadsides in the warmer parts of these islands.
In its land of origin, the chestnut crop was - still is - dried for winter stores and combined with lentils or chickpeas or haricots in winter stews. Milled to flour - sweetish and gluten-free - traditional uses are as a thickener for nourishing winter soups and as an ingredient, usually combined with cereal-flours, in traditional bread and cakes, particularly Italy's castagnaccio.
As storecupboard staple, the chestnut's chemical structure and nutritional value is just about identical to that of the potato, an infinitely adaptable, fast-growing New World starch-food that replaced the slow-growing, labour-intensive tree-nut in the Old World’s boiling-pot. For the rural poor of southern Europe, the chestnut forests that once rimmed the Mediterranean littoral provided forage for semi-wild herds of pigs as well as the difference between starvation and survival through the winter months. In medieval Britain, while the landlord reserved hunting rights to forest-game, the trees provided the rural poor with a storable starch-food, gleanings for a sty-pig and charcoal for cooking.
Chestnuts have a short shelf-life. To preserve in the freezer, skin, peel and bag when fresh. To dehydrate for storage, skin, peel and spread on newspaper in a warm, dry place and store as you would beans or chickpeas; when ready to rehydrate, soak in cold water overnight, then cook in boiling unsalted water for 20-30 minutes till tender, when you'll find very little loss of flavour and texture.
To oven-roast fresh chestnuts, score a deep cross on the flat side and roast on a baking sheet at a maximum heat for 20-30 minutes till soft, then roll in a towel and rub to crush the outer shell before peeling, taking care to pick off the bitter inner skin. To serve as a vegetable (with or without Brussels sprouts) toss with melted butter and a dusting of cinnamon. To serve as a dessert, combine roasted chestnuts with apple-slices fried in butter (cream and sugar optional - aren't they always?).
To boil fresh chestnuts (best for stuffings, puddings and icecream): slash as above and cook in unsalted water for 15-20 minutes; drain and allow to cool a little before skinning (don't wait till they're cold). For a chestnut spread (perfect for a büche-de-noel), sieve or mash, stir over a gentle heat with a splash of water and half its own volume of sugar till the mixture turns transparent, ladle into jars, cover tightly and store in the fridge.