Wednesday, November 17, 2010
Chestnuts are shiny brown nuts whose thick casing has long, sharp, needle-like spikes (burrs). There are usually two to four nuts per casing. Unlike other nuts, chestnuts have a high starch and water content but low protein and fat levels. They've never been as popular in British kitchens as in Continental ones, but they're a versatile and flavourful storecupboard ingredient. Chestnuts are available fresh, ground, dried, puréed or vacuum-packed.
Chestnuts trees have grown across China and Japan since ancient times. The Greeks brought them to Europe from Asia Minor and later they spread across the continent with the Romans.
For many Europeans in the eighteenth and nineteenth centuries chestnuts were an important staple food and Italians used them to make polenta before the introduction of maize from the New World.
Many varieties of chestnut tree exist. The trees take 20 years to fruit but remain productive for centuries.
Chestnuts are higher in carbohydrates and lower in fat and protein than other nuts. They contain fiber, potassium, iron, zinc and manganese.
After picking, chestnuts slowly dry out and shrivel. Choose nuts that are heavy for their size with shiny, smooth shells. Give a squeeze to check that the nut inside is plump and full.
Freshly picked chestnuts start off quite crisp and become more tender and chewy over the following days or weeks before deteriorating to a dry and floury texture. Storage at a cool temperature (e.g. the fridge) slows the ageing process.
Peeling chestnuts is a task to plan for when there's something good on the radio for an hour or so; attempting the job when you're in a hurry is likely to result in swearing and a long-standing hatred of a very fine nut.
Cut slits (or crosses) in the shells and part-cook the nuts either by roasting for 15 minutes or boiling for 20 minutes. The shells will now be fairly simple to break open. Removing the brown membrane on the nut is a fiddlier task (easier performed while the nuts are warm) and you will need to break open some nuts to get at the skin in the crevices.
Shelled and peeled, chestnuts can then be cooked according to recipe requirements (for mashing or pureeing they should have the consistency of cooked potatoes - test with a skewer).
Ham from pigs reared on a diet rich in chestnuts is highly valued in many areas of France, Spain, Italy and particularly Corsica (home to an annual chestnut festival in December).