Radicchio is a member of the composite family, and is a type of subspecies of chicory. Over time and thanks to the work of botanists and farmers, many different types of radicchio have developed.
Since ancient times, radicchio has been known for its characteristic flavor and cleansing and healing properties. It was cultivated early on, originally by planting wild seed in the fields and vegetable garden. The radicchio that you find today is the result of the experiments of 19th century agronomists who engineered particular plants using a technique called imbianchiamento, or “whitening.”
Radicchio di Treviso was engeeneered by a Belgian named Francesco Van Den Borre who lived in Italy and cared for the gardens of the villas in the Veneto. He applied the imbianchiamento techniques used in his country to radicchio plants to create white-veins in the red leaves, hence the name “radicchio rose di Treviso.”
The popularity of this vegetable has lead to its cultivation in countries far from the Treviso area, however radicchio from the Veneto is still known for its quality and the quantity of production. In 1996, radicchio di Treviso and its cousin radicchio di Castelfranco were given the IGP (indicazione geografica protetta) certification.
Radicchio di Treviso IGP
There are two types of radicchio from Treviso, early harvest or precoce and later harvest called tardivo. Besides being harvested at different times, there are noticeable differences also in the shape of the radicchio. The first is shorter and has more white veins than the other. Of the two, radicchio tardivo is certainly used more in the kitchen thanks to its crisp leaves, bitter taste and dark red leaves. In both cases the red color is the result of the imbianchiamento techniques, by preforcing the early harvest variety while it is still in the field, and preforcing the tardivo after it has been harvested.
The radicchio tardivo, which is harvested with a special machine, is placed in tubs filled with running water held at a constant temperature of about 53°F. The radicchio is then finished in sand beds that have been heated to 68°F. The radicchio is then cleaned and placed into boxes.
In addition to radicchio rosso di Treviso, many other varieties of radicchio are grown in the Veneto and are considered equally as prized. The Castelfranco IGP variety is a cross between escarole and rosso di Treviso. It is rosy white and green in color with bright red variegation. The radicchio rosso di Verona IGP is red due to the fact that it is harvested during the winter when the temperature is low. There are also varieties called radicchio di Maserà and radicchio di Lusià.
All the varieties have different culinary uses. Some are best eaten raw or used in salads, while others can be grilled or used to make sauces and pasta-fillings. Radicchio was originally used to flavor risotto and pasta.