Sweet Chestnut

A look at the sweet chestnut tree with facts and history.

Sweet chestnut, is a species of flowering plant native to Europe and Asia Minor, and widely cultivated throughout the temperate world.

A substantial, long-lived deciduous tree, it produces an edible seed, the chestnut, which has been used in cooking since ancient times.

The tree is commonly called the "chestnut", or "sweet chestnut" to distinguish it from the horse chestnut to which it is only distantly related.

The tree grows to a height of 20–35 meters with a trunk often 2 meters in diameter.

The bark often has a net-shaped pattern with deep furrows or fissures running spirally in both directions up the trunk.

The flowers of both sexes are borne in 10–20 cm long, upright catkins, the male flowers in the upper part and female flowers in the lower part.

In the northern hemisphere, they appear in late June to July, and by autumn, the female flowers develop into spiny cupules containing 3-7 brownish nuts that are shed during October.

The female flowers eventually form a spiky sheath that deters predators from the seed.

Some cultivars produce only one large nut per cupule, rather than the usual two to four nuts of edible, though smaller, size.

The tree requires a mild climate and adequate moisture for good growth and a good nut harvest.

Its year-growth is sensitive to late spring and early autumn frosts, and is intolerant of lime.

Under forest conditions, it will tolerate moderate shade well.

The species is widely cultivated for its edible seeds (also called nuts) and for its wood.

As early as Roman times, it was introduced into more northerly regions, and later was also cultivated in monastery gardens by monks.

Today, centuries-old specimens may be found in Great Britain and the whole of central, western and southern Europe.

A tree grown from seed may take 20 years or more before it bears fruits.

The raw nuts, though edible, have a skin which is astringent and unpleasant to eat when still moist; after drying for a time the thin skin loses its astringency but is still better removed to reach the white fruit underneath.

Cooking dry in an oven or fire normally helps remove this skin.

Chestnuts are traditionally roasted in their tough brown husks after removing the spiny cupules in which they grow on the tree, the husks being peeled off and discarded and the hot chestnuts dipped in salt before eating them.

Roast chestnuts are traditionally sold in streets, markets and fairs by street vendors.

Once cooked, chestnuts acquire a sweet flavour and a floury texture similar to the sweet potato.

The cooked nuts can be used for stuffing poultry, as a vegetable or in nut roasts.

They can also be used in confections, puddings, desserts and cakes.

They are used for flour, bread making, a cereal substitute, coffee substitute, a thickener in soups and other cookery uses, as well as for fattening stock.

This tree responds very well to coppicing, which is still practised in Britain, and produces a good crop of tannin-rich wood every 12 to 30 years, depending on intended use and local growth rate.

The tannin renders the young growing wood durable and resistant to outdoor use, thus suitable for posts, fencing or stakes.