Chestnut trees are native to temperate regions of the northern hemisphere, where they still grow wild.
Different species are cultivated: European, Japanese, Chinese, and American chestnuts.
But they are not recent trees! Fossilized chestnut leaves were found at Saint-Bauzile in the Ardèche region that date back 8.5 million years, to the Tertiary period.
There have always been chestnut groves: humans quickly learned how to graft, propagate, and prune them. The European chestnut has been cultivated for at least 3,000 years in the Mediterranean basin.
Proper chestnut cultivation in Europe started in the Middle Ages. Its spread was halted by the very strong frosts of the early 17th century, but resumed afterwards.
Whether in France, Italy, Spain, or Portugal, chestnuts have been a human staple for centuries, particularly in mountainous regions where they grew, and a source of food for livestock, such as pigs.
Development of society and economies led to a decline in demand for chestnuts and abandoning of their exploitation.
Output is modest in France, in the region of 11,000 metric tons mainly produced in the Ardèche, Dordogne, and Lozère regions, and Corsica. It also grows in Provence, especially in the Massif des Maures mountain range.
World chestnut production is 1 million metric tons. China is the leading producer (715,000 metric tons), followed by South Korea, Italy, Turkey, Bolivia, Japan, Russia, Greece, and France.
A chestnut should always have a smooth and very shiny shell. It should not have any holes: if there are, there will be worms feasting on the inside.
It should also be heavy and firm: when it is light and soft, it is old and not very good.
Chestnuts from the Ardèche region of France have PDO status.
Chestnuts are available fresh during the season. They are sold all year round, peeled and pre-cooked, frozen, vacuum-packed or in jars.
Chestnuts are made into:
- chestnut flour: Corsican chestnut flour has PDO status
- chestnut puree, canned or frozen
- sweetened chestnut puree, canned or in jars
- chestnut spread
- marrons glacés, whole or in small pieces
Chestnuts must be shelled, and the thin, very bitter skin covering the kernel must be removed.
In order to do this, they must be cut open, then immersed in boiling water, or spread out over a metal sheet in an oven at 200ºC for at least 10 minutes.
They should be peeled immediately afterwards. They can then be made into puree and soup, or roasted, used to garnish game, poultry (traditionally turkey), white meat, and even fish. They can be ingredients of forcemeat or a vegetable casserole.
Chestnuts are candied. Sweetened chestnut puree is one of the ingredients of Mont-Blanc. It can be a filling for crepes, desserts, cakes, and used for mousse, bavarois, and ice cream.
Chestnut flour is used for pancakes, crepes, and cakes.
Mixed with wheat flour, it can be used for all kinds of pastries.
Chestnuts can keep for several days in a cool place and for up to 2–3 weeks in a refrigerator or cool room.
Chestnut flour should be stored in its container and in a dry place.
Chestnuts are high in carbohydrates. For this reason it is considered a starch, despite being a fruit.
It is also rich in minerals, B group vitamins, and vitamin E. It also contains a great deal of dietary fiber.
It is also high in gluten-free proteins (which makes it unsuitable for baking on its own).
Chestnuts and chestnut flour are thus very useful for people with gluten intolerance.
The French distinguish two types of chestnut: the châtaigne and the marron, although both are green, thorny burrs.
It is what is inside that differentiates them.
The châtaigne is chambered and contains two or three chestnuts. The marron is a single nut.
Once the burr is removed, they are also differentiated by their shape and size. The châtaigne is slightly flattened, while the marron is rounded, and it is also larger.
Both have a hard brown shell enclosing a large whitish, floury, and somewhat crumbly kernel.
The word marron is also normally used to describe a large châtaigne! It is also used to describe all the products made from chestnuts, such as the renowned marron glacé.
In Europe, chestnuts appear in markets in September/October and last until February.
The chinkapin is the fruit of a small chestnut tree that grows on the east coast of North America.