Chianti, Chianti Classico and Super-Tuscan wines are all produced from the same varietal of grape, Sangiovese, which is grown in the Tuscany region of Italy. During the twentieth century, the Chianti producers focused on capturing market share and not producing quality wine, thus tarnishing the Chianti name. Chianti became associated with low prices and low levels of quality; the cheap and cheerful, light red Italian wine in a straw-covered bottle.
In an attempt to recapture the Chianti image of quality, wines from the region of Chianti Classico soon became the new focus. What sets Chianti Classico apart, is that it is a small specific area within the greater Chianti region possessing slightly different soils, climate and wine production methods. Decades later, another attempt to recapture the Chianti image of quality was the creation of the Super-Tuscans. This was another marketing tool to increase the prestige and price of the simpler and less expensive Chianti and Chianti Classico wines. Super-Tuscans are made from the same Sangiovese grape; however, they are blended with Cabernet Sauvignon or Merlot instead of the old world Trebbiano or Malvasia Biance grapes.
It turns out that a few twists on an old grape can squeeze a little more green stuff out of it.