During harvest, which generally takes place late in October, a deep, intense fog sets into the Langhe region where many Nebbiolo vineyards are located.

Alternative explanations refer to the fog-like glaucous veil that forms over the berries as they reach maturity, or that perhaps the name is derived instead from the Italian word nobile, meaning 'noble'.

As they age, the wines take on a characteristic brick-orange hue at the rim of the glass and mature to reveal other aromas and flavours such as violets, tar, wild herbs, cherries, raspberries, truffles, tobacco, and prunes.

Ampelographers believe that Nebbiolo is indigenous to the Piedmont region, though there is some DNA evidence to suggest that it could have originated in the Valtellina area of northern Lombardy, just to the east.

[3] In the 1st century AD, Pliny the Elder noted the exceptional quality of the wine produced in the Pollentia region located northwest of what is now the Barolo DOCG zone.

In the 1304 treatise Liber Ruralium Commodorum, the Italian jurist Pietro Crescenzi described wine made from "nubiola" as being of excellent quality.

[2] The grape first captured attention outside Piedmont in the 18th century, when the British were looking for alternative wine sources to Bordeaux due to prolonged political conflicts with the French.

However, the lack of easy transport from Piedmont to London would keep the Piedmontese wine from having the enduring relationship with British connoisseurship that is associated with Bordeaux, port and sherry.

[4] To aid in ripening, producers will often plant Nebbiolo in the most favoured sites on south and southwestern-facing slopes, which give the grape more access to direct sunlight.

In cooler climate areas, such as the subalpine regions of Carema, Valtellina and Donnaz, the grape will produce medium bodied wines with bracing acidity and tannins that need the benefit of a warm vintage.

Its impact is limited by the fact that Nebbiolo Rosé had fallen out of favour long before the discovery that it was a separate variety, due, in part, to its wine's light colouring.

While Michet adapts less readily to different soil types, its smaller bunches and lower yields makes for highly concentrated wines.

In general, the traditional approach to Nebbiolo involves long maceration periods of 20 to 30 days and the use of older large botti size barrels.

The modern approach to Nebbiolo utilizes shorter maceration periods of 7 to 10 days and cooler fermentation temperatures between 82 and 86 °F (28 and 30 °C) that preserve fruit flavours and aromas.

Modern winemakers tend to favour smaller barrels of new oak that need only a couple of years to soften the tannic grip of the wines.

While there is some speculation, from critics such as Oz Clarke, that Barbera or even Syrah and Cabernet Sauvignon may be used to augment the colour and flavours of Barolos by some producers, there is no explicit proof that this is occurring.

In the Valtellina region of Lombardy Merlot, Pinot nero, Pignola, Prugnolo, and Rossola are permitted blending partners for Nebbiolo.

The consistent continental climate of the region, coupled with the influences of the Tanaro River produces a unique terroir for Nebbiolo that is not easily replicated in other parts of the world.

In the west, the communes of La Morra and Barolo have soils dominated by chalk and marl and produce wines that are more perfumed and silkier in texture.

[4] Outside Barolo & Barbaresco, Nebbiolo is found in the DOCG wines of Ghemme and Gattinara in the Novara and Vercelli hills of northern Piedmont.

In the northwestern corner of Piedmont, near the Valle d'Aosta, the cool climate of Carema DOC produces Nebbiolo wines with much perfume but in some vintages will have difficulties with ripeness.

In the Roero district located across the Tanaro River from Barolo and Barbaresco, the wines tend to be less tannic and lighter while those produced in nearby Alba under the Nebbiolo d'Alba DOC can have more complexity and body.

Today there are scattered plantings of Nebbiolo throughout the state with the majority located in the jug wine producing region of the Central Valley.

[11] In Australia, winemakers found little early success with Nebbiolo as many of the earliest plantings were inland sites that turned out to be too warm and dry for the grape.

Research into cooler-climate sites leads to more favourable examples coming from the marginal climate of Victoria's King Valley, and the cooler Adelaide Hills.

Further studies have indicated that the Mornington Peninsula and the Margaret River areas have similar amounts of rainfall, relative humidity and sunshine hours to the Langhe region of Piedmont.

In most cases, the Australian regions where the variety does best tend to be ones where clouds of fog are not an uncommon sight in autumn and winter – inland and up high.

In South America, early results in Chile have so far produced wines with high acidity and poor colour as winemakers work to find which clones are best suited for their climate.