Barolo wines are made from 100% Nebbiolo grapes, a famous red grape variety for fine-tasting wines, the most unique and remarkable grape varieties of the appellation, with typical aromas such as raspberry, red currant, blueberry, cherry, rose, violet, truffle, smoke, chocolate and pepper. Nebbiolo is a variety with thin skin and small grains, with hard skin and good frost resistance and disease resistance. When the fruit is close to ripening, a mist-like hoarfrost will form on the skin. The source language of its name "Nebbia" means "fog" in Piedmontese, so it is also called "fog grape". Nebbiolo is extremely picky about its growing environment. Compared with other grape varieties in Piedmont, Nebbiolo has a long growth cycle, early germination but late harvest, and the harvest period is usually from mid-October to the end of October. In addition, the requirements for light and soil are quite high. In order to accumulate sugar and achieve satisfactory maturity, the best planting location is a sunny vineyard. The best quality Nebbiolo grapes are generally planted at an altitude of 250-450 meters.

Barolo must be aged for at least 3 years in oak barrels, of which at least 18 months must be in wood. The top Reserve needs to be aged for 5 years. It usually has aromas of tar, rose, and violets, and is deep ruby (or cherry red) in color and full-bodied. High acidity, alcohol and tannins, with aging ability.

In the past, Barolo wines tended to be rich in tannins and took more than 10 years to drink well. Because the wine takes at least three weeks during fermentation, during which a lot of tannins are extracted, and then aged for several years in large wooden barrels. Now, if you want to drink it earlier, some producers shorten the fermentation time to a maximum of ten days and age it in new French oak barrels (small barrels), in order to be more attractive and complex.

In the 19th century, Barolo was considered a sweet wine. Nebbiolo grapes ripen in late October, which means temperatures will drop after harvest. By November and December, temperatures in the Piedmont region will be cold enough to stop fermentation, which leaves a lot of residual sugar in the wine. Another popular theory is that in the 19th century, Camillo Benso, the mayor of Grinzane Cavour, invited French winemaker Louis Oudart to the Barolo region to improve the winemaking techniques of local producers. Using techniques focused on improving cellar hygiene, Oudart was able to ferment Nebbiolo to a completely "dry" wine, the first modern Barolo. This new "dry" red wine quickly became a favorite of the nobility, leading Barolo to call it "the wine of kings, the king of wines".