Treviso, Veneto. The forcing technique for radicchio Tardivo was developed in the 19th century in the countryside around Treviso. IGP status granted in 1996. The Confederazione del Radicchio Rosso di Treviso supervises the production standards.
Radicchio Tardivo is one of the most extraordinary Italian vegetables: a late-season chicory from Treviso with long, curved, crimson-and-white leaves with a distinctive bitter-sweet flavour that develops through a forced growing process. After the first autumn frosts kill the outer leaves, the plants are uprooted, roots placed in circulating cold spring water in the dark for 3-4 weeks. This 'imbianchimento' (blanching) draws the plant's stored sugars to the tender new shoots that emerge in darkness, creating the characteristic elongated curly leaves. The result is less bitter and more complex than standard radicchio.
The forcing transforms the bitterness of field-grown radicchio into a nuanced, sweet-bitter complexity. Grilled, the edges char and sweeten; the ribs remain slightly crunchy with a bitterness that is appetising rather than harsh. In risotto, the radicchio gives the dish a deep wine-like colour and a flavour that is uniquely Trevisan.
The imbianchimento (forcing) is the defining production technique — the plant must be in cold, moving water in darkness for 2-4 weeks for the quality transformation to occur. Tardivo radicchio is harvested in December-January. In the kitchen, the correct treatment is simple: grilled over charcoal or wood fire (the high heat caramelises the natural sugars and tames the bitterness), or served raw with very good olive oil and aged balsamic vinegar. The leaf structure — long curling white ribs with dark red tips — means it grills unevenly if not watched. Risotto with Tardivo is one of the Treviso restaurant standards.
Tardivo grilled with olive oil and seasoned only with salt is one of the simplest and best Italian vegetable preparations. For risotto, add the radicchio near the end of cooking — it should wilt but retain colour. Its natural sugar caramelises in a very hot pan and produces an extraordinary depth. The roots are edible and can be sliced thin and eaten raw in salads.
Overcooking when grilling — it should be charred at the edges but still crunchy inside. Using early-season radicchio as a substitute — regular radicchio is much more bitter and less sweet. Drowning in dressing — the flavour of forced radicchio is delicate and should be highlighted, not masked. Chopping too finely — the whole leaf structure is part of the eating experience.
Giorgio Locatelli, Made in Italy; Slow Food Editore, Veneto in Cucina