There’s a vegetable you’ve probably never seen in the supermarket. It has a bizarre, at times disturbing shape, similar to small white caterpillars, but also to pearls strung on an invisible thread. Behind this unusual appearance lies an ancient and refined vegetable, forgotten for decades and now rediscovered by great chefs. Is called Stachys affinisa plant belonging to the family Lamiaceae (the same as, among others, basil, rosemary, sage, mint and thyme) and known by more evocative names, such as crosne, tuberina or Chinese artichoke.
A vegetable that comes from far away
Native to central and northern China, this plant was already cultivated in the 13th century. Unlike its aromatic relatives, the tuberina produces edible rhizomes underground, about 8 centimeters long and 2 centimeters thick, with that characteristic spiral shape that makes them unmistakable.
The plant grows like a bush reaching between 30 and 120 centimeters in height, with rough leaves similar to those of nettles and red to purple flowers. But it is underground that the magic happens: the tubers develop with narrowings at irregular intervals, creating that peculiar segmented shape. The peel is thin, light beige or ivory in color, while the internal pulp is white and tender.
The crosne’s journey to Europe
In 1882 the cultivation arrived in Europe for the first time, precisely on a farm in Crosne, a French municipality from which it took the name by which it is still known today beyond the Alps. France was the first European country to import this ancient vegetable from the East and still remains the place where its culture is most deeply rooted.
At the beginning of the 20th century, crosne enjoyed some popularity in Europe. Alexandre Dumas mentioned it in 1887 as an ingredient in his “Japanese salad” in the play “Francillon”. During the world wars it became an important food, although this association with periods of deprivation contributed to its decline after the war. In the 1970s, cultivation was abandoned due to viral problems and the plant’s strong tendency to spread like a weed. Only from 1990 onwards was there a new recovery, with large haute cuisine restaurants bringing this precious ingredient back to light.
How tuberina is grown
Growing Stachys affinis is relatively simple. It is a rustic plant that adapts to any vegetable garden or garden, although it prefers well-drained soil and sunny positions. The plant appreciates some shade during the hottest summer, while it needs good sun exposure the rest of the year.
Sowing is carried out in spring, between March and May, planting the tubers at a depth of 5-8 centimeters in holes spaced about 30 centimeters apart. During the summer, regular watering is needed, taking care not to create water stagnations which the plant is particularly afraid of. Weeding is necessary, taking care not to damage the roots.
The harvest takes place from November to March, when the aerial part of the plant has dried. It is essential that the ground is not frozen during harvesting. Tuberin has an annoying characteristic: it tends to infest the garden if it is not controlled. However, it is enough to uproot the shoots 3 or 4 times the following year to get rid of them completely.
Conservation: a challenge against time
Herein lies the main problem with crosne. The very thin skin means that the tubers can only be kept for a few days, a maximum of a week in the refrigerator. They wither and deteriorate very quickly in the air, so much so that they should be collected and consumed the same day. This characteristic, combined with the difficulty of mechanizing harvesting and cleaning, explains why crosne is so rare and expensive on the market.
The particular flavor of tuberina
Crosne has a crunchy texture and a sweet, delicate flavour. Depending on the preparation, it resembles artichoke (hence the alternative name), hazelnut, Jerusalem artichoke or salsify. It is rich in stachyose, a tetrasaccharide made up of galactose, glucose and fructose, which makes it highly digestible and nutritious.
How to cook crosne
To prepare the tubers, clean them under running water, delicately scrubbing the thin skin with a brush to remove soil residues. There is no need to peel them and they can be eaten raw, cut into small pieces in salads, to appreciate their crunchiness and delicate flavour.
The simplest cooking involves blanching them in salted water for about 10 minutes, then draining them and sautéing them in a pan with garlic, oil and parsley, a method that enhances their particular flavor and makes them a perfect side dish for roast meats, especially poultry.
In Asian countries, where crosne has been part of the culinary tradition for centuries, it is mainly prepared in brine or lacto-fermented. In Japan the red colored tuber with perilla leaves is part of osechi, the traditional New Year’s meal, and is called chorogi.
In contemporary Western cuisine, great chefs use crosne for refined salads and gourmet side dishes. It is also suitable for baking, seasoned with spices and aromatic herbs. The leaves of the plant can be dried and transformed into an infusion with a particular flavor.
The rarity of the crosne, the extraordinary shape and the unique flavor make it a precious ingredient for those who love to experiment in the kitchen. It is worth looking for it in the farmers’ markets between November and March, or better yet try growing it in your own garden, because this forgotten rhizome deserves to return to our tables.
