The walnut tree has always grown in a vast region stretching from south-eastern Europe to the Himalayas. Traces of walnuts have been found in a large number of archaeological sites, from Iraq to the Dordogne: the Cro-Magnon loved his walnuts!
Throughout the ages, over the course of various conquests, and due to the construction of trade routes, the walnut spread throughout all temperate countries. Humans have always preferred to eat the fruit of the walnut tree, which is considered much tastier than acorns or chestnuts, and they quickly learned to extract oil, as they did from the fruit of the olive tree.
The Romans thought that the walnut was a sacred tree.
In France, in the Middle Ages, walnuts and walnut oil were used as currency. The oil had many uses, not only as food, but also in cosmetics and as a cleaning tool, as it was used to lighten surfaces. Until the 19th century, walnut oil was most commonly used oil in central France.
Fresh: the walnut is a fragile product that rots quickly. Some producers pick them to order.
Dry and in their shell: they must not be more than 6 months old. If a nut rattles when you shake it, this means that the kernel has dried out and is unusable.
Kernels: they must not be more than one year old.
Walnut oil: preferably virgin, or pure otherwise.
Walnuts in their shell, fresh or dried: in nets, bags, or trays.
Kernels: in bags of varying weight (2.5 kg, 250 g, 125 g), whole or in halves.
Crushed, in powder form: in bags, often vacuum packed.
Walnut oil: in 50 or 25 cl bottles.
Walnuts in a shell should be broken with a mallet rather than a nutcracker, which can crush the kernels.
Chopped walnuts are a welcome addition to salads (they are a mandatory ingredient in the Waldorf salad), stuffings, soups, pasta, risotto, and chutney. They can replace pine nuts in pesto and add crunch to bread. They also add crunch to a vegetable garnish for meat or fish.
Walnuts go well with endives, beets, and many cheeses.
In powdered form, they can replace, or be combined with, bread crumbs.
Salsa di noci (walnut sauce) is part of the Italian culinary heritage.
Walnuts are a common ingredient in pastry and confectionery, as their slight bitterness (especially if they are not peeled) balances out the sweetness of sugar or honey. They also add a decorative element.
Walnut cake and pie are classic dishes. But they are also added to cakes, brownies, fondants, cream-based desserts, meringues, and stuffings, along with other dried fruit and nuts.
They always combine extremely well with chocolate, honey, caramel, or chestnuts.
Walnuts are an ingredient in mendiant cookies and they are a classic addition to fruit déguisé, or marzipan fruit.
Fresh walnuts can be stored in the refrigerator or cold room at 4 °C but should be used as quickly as possible.
Dry walnuts and kernels must be kept in a dry place, away from moisture and heat, or in the refrigerator.
It is the same for nut powder sachets, which have a BBD (best before date) because the powder goes off very quickly.
Walnut oil should be stored in a dark place and, once the bottle has been opened, in the refrigerator.
The walnut is very high in fat, much of which is polyunsaturated (this is why it rots very quickly), containing a lot of Omega 3. It is also rich in various antioxidant compounds, which gives it protective qualities.
It also contains protein and carbohydrate. It has high levels of minerals, B vitamins, vitamin E, and fiber.
As they contain less water than fresh walnuts, the dry nuts have a higher nutritional value.
In France, there are two main types of walnut, each protected by an AOC (controlled designation of origin) and a PDO (protected designation of origin) and from different varieties of walnut tree. These two types are:
. Grenoble walnuts: Franquette, Mayette, and Parisienne are the varieties protected by the AOC issued on June 17, 1938, making this nut the first fruit to be certified in this way. Isère, and part of Drôme and Savoie, are producing regions.
. Périgord walnuts: Corne, Franquette, Grandjean, and Marbot are the varieties covered by the most recent AOC (2002) and are grown in the Dordogne, Lot, Corrèze, and Charente.
Various other varieties of walnut exist in France outside of these regions.
Walnuts are also grown in other European countries: Greece, Italy, Spain, Portugal, Chile, Argentina, and China. These walnuts are made available through export. The black walnut tree is popular in North America and produces slightly larger walnuts than the European varieties.
In France, fresh walnuts are available from mid-September through late October.
Dried walnuts in their shell are sold in fall and winter.
Shelled walnuts (kernels) are sold throughout the year.
- Walnut oil
Virgin: it comes from high-quality walnut kernels, often lightly toasted.
Pure: this is a mixture of virgin walnut oil and refined walnut oil in varying proportions depending on the producer.
Refined: it is extracted from walnuts, which, after sorting, were judged unfit for consumption. Refining removes most of the flavor and aroma.