Two nuts, one crucial difference
Two very different nuts fall at roughly the same time each autumn, and one of them will make you ill. Getting them straight before you pick up anything from the ground is the single most important thing about chestnut season.
The sweet chestnut (Castanea sativa) is the edible one. Its case is a ferociously dense sphere of long, needle-like spines – genuinely painful to handle bare-handed. The nuts are flattened on one side, tapering to a point at the other with a small, fibrous tassel at the tip. The shell is a warm mahogany brown.
The horse chestnut – the conker tree – produces something superficially similar but distinct on every count. Its case has sparse, stubby spikes and a thicker, bobbly skin. The nut itself is rounder and glossier, with no tassel, and sits in a white, padded interior. Horse chestnuts contain compounds that cause significant digestive distress. When in doubt, leave it where it fell.
When and where to look
Sweet chestnuts come into season through October and into November. The nuts fall when ripe – you rarely need to pull them from the tree. A long stick to roll cases open on the ground saves a lot of discomfort.
The great sweet chestnut coppices of Britain are concentrated in Kent and the south-east, where the tree has been worked for centuries. The long, straight poles used for cleft fencing and hop gardens are as much a part of its history as the nuts. Ancient coppice woodland in this part of England can feel cathedral-like in autumn: high canopy, open floor, ground littered with spiny cases. The tree thrives across southern England more broadly, and fine specimens turn up in estate parkland, old churchyards and National Trust properties well beyond Kent.
British sweet chestnuts run noticeably smaller than the large, cultivated varieties imported from France, Spain and Italy. This is not a flaw. Smaller nuts tend to have a higher ratio of dense, sweet flesh to thin inner skin, and they roast beautifully.
A street food older than most
Roasted chestnuts sold from braziers on winter streets are one of the oldest cold-weather street foods in Britain. The smell – smoky, slightly sweet, with that particular scorched-shell quality – is as much a marker of the season as anything you might see or hear. Score the nuts across the flat side before roasting to stop them bursting, and eat them warm, peeled back from the charred shell.
Beyond roasting, sweet chestnuts have a long culinary history across Europe that Britain has largely borrowed rather than developed independently. They are ground into flour in parts of France and Italy, puréed and sweetened in classic French confectionery, and used in stuffings throughout the winter. The flour is naturally gluten-free with a mild sweetness – a specialist ingredient, but increasingly available from independent food merchants.
The Roman question
The sweet chestnut is not a British native. It was almost certainly introduced, and the Romans are the most likely candidates, bringing it as a food crop. Whether or not that attribution is precisely correct, the tree has been here long enough to feel entirely at home. In the old coppice woods of the Weald it is as much part of the landscape as oak or hazel, and has shaped the woodland management traditions of those counties as decisively as any native species.
For those new to foraging, a chestnut coppice in October is one of the more forgiving places to start. The identification is clear once you know what you are looking at, the harvest is generous in a good year, and the reward – even a handful of nuts roasted at home in a dry frying pan – is immediate and satisfying.
