Chestnuts roasting on an open fire

Chestnuts over the hot coals: a mixture of two species of Castanea.

 I have always loved eating the autumn and winter ritual of cooking chestnuts. My earliest memories are of cooking them under the grill when we had no fireplace, and then, in another home, roasting them in an old fashioned chestnut pan over an open fire. From childhood, too, come memories of my grandmother buying us small bags of chestnuts from what she called a 'brassiere' on the street in London. When I've not had a fireplace to hand I've found that one can microwave them quite successfully  - just make sure they're well pricked, with the ends cut off, to avoid very messy explosions - and boiling them is successful too. Neither of these methods gives the traditional partially scorched flavour from roasting them over the coals, though. With open fireplaces in this house I've been able to get back to roasting them properly. As with a barbecue one really needs to put them over hot coals rather than a briskly burning fire, and then shoogle them about to prevent them burning in one place. They don't take long, about ten minutes.

The traditional edible chestnut in Europe is the Sweet Chestnut, Castanea sativa, potentially a magnificent big tree with many fine ornamental characters. It doesn't fruit reliably in this country, so finding trees with a good crop of nuts just adds to the pleasure. The nuts are therefore imported from southern Europe, mostly Italy. They're not very big - 3 cm across would be large. When I was in Vancouver a few years ago I got a bag of chestnuts from a 'brassiere' (an indelible malapropism) and noticed they were much larger than normal. In the past two or three autumns I've seen the same nuts for sale here, and although I knew they weren't C. sativa I didn't pay them much attention. This year I bought some to make a deliberate comparison and to try to identify them.

Chestnuts from China, either Castanea mollissima or C. crenata. The enormous dark hilum (seed scar) is very obvious.

 It's clear that they are imported from China, so the obvious thing was to try the Flora of China. Two species are grown there commercially for edible nuts: the native C. mollissima and the Japanese C. crenata, but the descriptions of the nuts are insufficient for an identification. They have clear foliage differences, however, so I'll grow on a few and see how they are in spring. The nuts are very much larger (4 cm + across) and 'chunkier' than C. sativa, usually a rather triangular shape, and have a very large hilum, or scar, where the nut was attached to the capsule. This is very distinctive.

A comparison of two species: the Chinese nuts (left) and  Italian C. sativa  (right) the differences in size, colour, hilum, etc, are very visible.

I carefully tested the flavour by both roasting and boiling nuts together. There is no doubt that for flavour C. sativa wins hands-down: sweet and soft-textured.  The Chinese nuts are much more coarsely textured and have only a whisper of sweetness. They're not unpleasant, but they're pointless if C. sativa is available. I just hope that in this case the European goods can hold up their market share against Chinese imports...