Biondi Santi is a Tuscan producer synonymous with the wines of Brunello di Montalcino and, indeed, has claims to being the inventor of the style. The wines are fragrant and floral with savoury hints, with bright berry and cherry fruit and peppery spice over a backbone of fine tannins and acidity. Riservas are only released in the best years, can last for many decades and often need 15 or more years to be tasted at their best.

The Biondi Santi vineyard has 25 hectares (62 acres) of Sangiovese, of which 5ha (12 acres) were planted between 1930-1972. These form the basis of the Riserva wines, while the standard wine is made from vines in the 10-25 year bracket. Fruit from vines under 10 years old supplies the dry, brightly aromatic Rosso di Montalcino. In poorer years when no Brunello is released, Biondi Santi makes a second Rosso di Montalcino called Fascia Rossa with fruit from the older vines.

The grapes are picked relatively early for the region, and then undergo a long maceration. Most of the grapes are fermented in resin-lined cement using native yeasts, except for those destined for the Riserva, which are vinified in wooden vats. The wines are then aged for 36 months in large, neutral Slavonian oak casks, while the Rosso wines see 12 months. Biondi Santi does not use new oak, as it is thought to add aggressive tannins to the naturally tannin-rich Sangiovese.

The history of the estate and the entire region are closely related. Indeed, the first recorded mention of a Brunello was at Montepulciano's agricultural fair in 1869, referencing Clemente Santi's "vino rosso scelto (Brunello) del 1865" (although the family's Greppo vineyards were well established by then). In 1932, the Italian Ministry of Agriculture referred to Brunello as "a recent creation of Dr Ferrucio Biondi Santi from Montalcino".

Ferrucio Biondi Santi, during the problems with oidium and phylloxera in late 19th Century, developed massal selections of his most resistant vines, later grafting them onto American rootstocks, and continued to make an oak-aged red from 100 percent Sangiovese while other producers disappeared or moved to different wine styles. By the end of World War II, Biondi Santi's Tenuta Greppo was one of the few estates left in Montalcino, growing a specific variant of Sangiovese not seen in the rest of Tuscany. Much of the expansion of the appellation from 1970 is based on cuttings from their vines, and Biondi Santi clones are commercially available today.

Jacopo Biondi Santi, who now runs the estate with his sister Alessandra, also owns Castello di Montepo, an estate in Scansano in the Maremma Toscana.