The imposing hill of Montalcino in southern Tuscany stands like a giant pyramid, surrounded on all sides by the Asso, Orcia and Ombrone rivers. It wasn't until 1888 that the Biondi-Santi family linked the sangiovese grape to Montalcino's unique soils and climate to create one of Italy's intense and expensive examples of brunello di montalcino. Sitting at the apex of this pyramid, some 10 miles across, the walled town of Montalcino itself has long been the focus of historic struggles against successive oppressors. After the war, it lost 70 per cent of the population and only six estates survived.

Today, success has brought a new form of oppression. A surge in demand followed the grant of Italy's first DOCG (denominazione di origine controllata e garantita) in 1980, but the declining buying power of traditional overseas markets has left brunello high but far from dry.

Few wine zones in the world demonstrate quite so dramatically the significance of terroir. Even within Italy, no zone offers such a vivid expression of the sangiovese grape. Chianti classico is starting to work on pure sangiovese after the recent rule change allowing it, but brunello has been using pure sangiovese for over a century.

Despite the blip in demand, there's a spirit of cooperation here in a country so often riven by rivalries and cut-throat competition. Styles of brunello vary from classically austere to the more fruity blandishments of the modern school.

In 1978, two American brothers, John and Harry Mariani, bought land and bulldozed the bumps from the slopes. They planted white grapes for a sweet asti spumante-like bubbly, but consumers were tiring of whites, so they converted to red, while researching the best sangiovese types to plant and where.

As Rudy Buratti, the chief winemaker of their company Banfi, points out: "You need to know the terroir to translate it into wine." Because of its power, vibrant sour-cherry acidity and tannins, brunello has always been a wine that's required ageing, but the rules have changed to allow a reduction from three and a half years in barrel to two, while rosso di montalcino is released sooner for earlier drinking.

Castello Banfi makes a fifth of all brunello and Banfi's prices are reasonable. Its brunello is a good entry point, although the velvet-textured, cherry-fruit concentration of Banfi's 2001, Poggio Alle Mura, is worth the extra, reduced to £22, Majestic Wine Warehouses, until 5 February.

Now is the time to buy the classic 2001 vintage (and riservas later this year, if you can afford them). Subsequent vintages are less good and the fine 2004 brunello will take some time to appear. On the rosso front, try the refreshingly cherryish 2004 Sesti, £14.50, Jeroboams (020-7288 8888), the equally voluptuous 2004 Fuligni, £13.95, Lea & Sandeman (020-7244 0522) or 2004 Talenti Rosso, Bibendum (020-7449 4120). Moving up to brunello itself, the 2001 Barbi Brunello, around £27.50, Cambridge Wine Merchants (01223 568991), Fortnum & Mason (020-7734 8040), Luvians (01334 477752), is in classic mould, perfumed, spicy and potentially long-lived, the fine 2001 Il Poggione, around £27.50, D Byrne & Co (01200 423152), Edencroft Fine Wine, Cheshire (01270 625302), a wonderfully precise traditional style; and Bibendum has half-bottles of the concentrated 2001 Talenti, £11.99. At the highest level, try the fabulous 2001 Sesti, £30, Jeroboams, intense, classy and pure, and the magnificently expressive, sour-cherry, yet austere 2001 Fuligni, £29.95, Lea & Sandeman, for a taste of what the fuss is about.