Nebbiolo, one of Italy's most noble grapes, makes Barolo, which is known as the "Wine of the Kings". Sangiovese is Italy's most widely-planted grape and is also the most widely-planted grape of Toscana.
Let's first look at the classic textbook descriptions of the taste profile these two grapes: Nebbiolo is tar and roses, together with its high tannin, acidity and alcohol. Sangiovese is sour and bitter cherries and violets with some tomato-leafy savouriness with some herbal and tea-like finish. Fair enough?
However, these two grapes are often confused when tasted blind. It is because the aroma and flavour descriptors of tar, violets, dried cherries, rose petals, leather and black tea notes seem to apply to both of them. Bottle ageing also often gives them greater complexity with similar layers of dried herbs, spice, liquorice and dried fruits. Also, structurally, wines made from both grapes are high in tannin and acidity with medium to high alcohol (Nebbiolo may often have a bit higher alcohol level).
Furthermore, both of the grapes can produce wines of huge stylistic diversity. The differences in style may come from the clonal and climate variations in specific regions (Barolo, Barbaresco, Gattinara, Ghemma, Valtellina for Nebbiolo and Chianti, Chianti Classico, Brunello di Montalcino, Vino Nobile di Montepulciano for Sangiovese). Generally cooler sites would produce wines with more delicate aromas, less ripe fruits and lighter body while warmer areas give riper fruit and firmer tannins. Style variations may also result from different winemaking options: the use of blending grapes in case of Sangiovese, harvest time with different level of ripeness, long or short period of maceration and maturation, choices of fermentation vessels (stainless steel, cement, oak, etc), use of large botti (Slovanian or French) or small barrels, old or new oak, etc). So it is really a challenge to tell which is which from a blind tasting of a mixed bag of the above!
At a wine lunch gathering, we called each friend to bring along either a Piedmontese Nebbiolo or a Toscana Sangiovese for blind tasting and to see how well we can distinguish the two grapes. Out of our surprise, with six bottles of wine sticking to the rule of the game, there were five Sangiovese and only one Nebbiolo. Frankly and as expected, we mistook some of those Sangiovese's for Nebbiolo's!
The six bottles in the row were:
Il Poggione 2009 Brunello di Montalcino
Medium ruby with orange rim. Lifted cherry with herbal and spicy notes. Sandy tannins.
Col d'Orcia, Poggio al Vento Riserva 1990 Brunello di Montalcino
Concentrated bright ruby with brick red rim. Very good fruit concentration with rich, chewy tannins. We were surprised by its power and liveliness given its age. Most mistook it for Nebbiolo!
Antinori, Pian delle Vigne 1996 Brunello di Montalcino
Medium crimson. High-toned nose. Ripe red fruits with gentle and velvety tannins. Refreshing acidity.
Mastrojanni 2010 Brunello di Montalcino
Medium ruby with brick-stone colour rim. Layers of dried fruit, red fruit and tobacco, with a full body and chunky tannins.
Bruno Rocca, Rabajà 1997 Barbaresco
After four Sangiovese, the highly perfumed notes of tea and roses seemed to have wakened us up. Ah! That's classic Nebbiolo! Good red fruit there, then came the earthy notes. Serious grainy but pleasant tannins.
Fontalloro 1997 Toscana IGT (100% Sangiovese)
Dense ruby, ripe cherry with cocoa and coffee notes. Full body and powerful. Slightly dusty tannins. Very long finish.
Perhaps the best way of telling them apart is by the texture of the tannins. When young, the wines of both grapes would have a high level of grippy, if not harsh, tannins, which would mellow over some years of bottle ageing. Nebbiolo tannins would tend to be grainy, and Sangiovese tannins are more of dusty and powdery. Of course, different vintages of wine in a row would make it harder for comparison. So we have not been convinced yet and will look forward to trying a second round!