Radicchio is a much-misunderstood vegetable. It is not a lettuce, not a cabbage (sometimes it is confused with red cabbage), but rather a form of slightly-bitter, slightly-spicy chicory, related to Belgian endive.
Radicchio has been around for quite some time: Roman naturalist Pliny the Elder mentions the marvelous red-lined lettuces of the Veneto region in his encyclopedic Naturalis Historia, circa 79 A.D., noting that in addition to being tasty, they're good for insomnia and purifying the blood; he also says it was the Egyptians who bred radicchio from its wilder ancestor, chicory.
In the Middle Ages, it was especially popular among monks, who welcomed anything that would add zest and flavor to the simple, predominately vegetarian diets proscribed by their orders. Not that the plant was limited to monastic kitchens; it also figured prominently on the tables of nobles, both cooked and raw: In 1537, Italian author Pietro Aretino advised a friend to plant it in his garden, saying he much preferred it to "aroma-free lettuce and endive."
While tasty, this radicchio wasn't the same as the radicchio rosso we know today: the modern radicchio, with its rich leaves ribbed in wine red and white, was developed in the 1860s by Francesco Van Den Borre, a Belgian agronomist who applied the techniques used to whiten Belgian endive to the plants grown around Treviso. The process, called imbianchimento, is quite involved: the plants are harvested in late fall, their outer leaves are trimmed and discarded, they're packed into wire mesh baskets, and they're stood for several days in darkened sheds with their roots bathed in steadily circulating spring water that emerges from the ground at a temperature of about 15 C (60 F). As they bathe, the leaves of the hearts of the radicchio plants take on the pronounced wine-red color that distinguishes them (the deeper the red, the more pleasingly bitter the plant). At this point, the farmer unties the bunches, strips away the outer leaves, trims the root (the tender part that's just below ground level is tasty), and sends the radicchio to market.
There are many different kinds of radicchio; here are the most important:
- Radicchio Rosso di Treviso. The best, it comes in two varieties: Precoce, which has fleshy red leaves with white ribs that form a compact bunch, and Tardivo, which has much more pronounced ribs and the splayed leaves. Precoce comes into season first, and though it is prettier to look at, the tardivo is more flavorful, with stronger bitter accents. Both Precoce and Tardivo now enjoy IGP (Indicazione Geografica Protetta, Protected Geographical Indication) status, which means that they can only be sold as such if they are produced around Treviso, under the supervision of the Consorzio Radicchio di Treviso.
- Radicchio Variegato di Castelfranco also enjoys IGP status; it looks more like a traditional head of lettuce but has deep wine-red stripes, and is also known as the Edible Flower. It's a cross between radicchio and a round-headed endive.
- Radicchio Rosso di Chioggia was bred from the Variegato; it has dark red leaves with white ribs, but is rounder than Radicchio di Treviso; it's also compact, and as a result, it resembles a head of cabbage in shape. It's now the most commonly grown radicchio rosso in Italy and is (alas) sold as radicchio di Treviso in other parts of Europe. I've also seen it in seed catalogs in the US.
- Radicchio Rosso di Verona was bred from rosso di Treviso in the 1950s and is somewhat longer and more oblong than its ancestor.
Radicchio, like almost everything else in Italy, is quite seasonal, appearing in the markets in late November and remaining throughout the winter; it's tastiest after the frosts begin, and is therefore worth waiting on if the winter is mild. It has also been introduced to California's Napa Valley and is becoming popular in the U.S. too. Small wonder; it's quite good. It's also good for you; radicchio's bitterness is due to intybin, which stimulates the appetite and digestive system, and acts as a tonic for the blood and liver.
Now That You've Bought Some Radicchio, What to Do With It?
When you get it home, put it in the crisper section of your refrigerator. It will keep for a couple of days, and if it looks slightly wilted, stand it in a glass of water—the tap root isn't just there for show; it also has nutrients that feed the leaves and can absorb water. When you trim the root prior to using the radicchio, don't discard it, but rather use it as you would a radish or other root vegetable.
Our favorite way to prepare them is quite simply, grilled and drizzled with a great extra-virgin olive oil and sea salt. So simple, and yet one of the best things we have ever tasted.
Some Radicchio Recipes:
[Edited by Danette St. Onge]