Pinot grapes come in a great variety and not only are they related, many varieties are quite closely connected through DNA.
However, before getting too far in this discussion it is important to point out that Pinot Gris and Pinot Grigio are in fact the same grape. Confusion sometimes arises from there being two names. Pinot Gris is what the grape is called in France, while the term Pinot Grigio originates in Italy.
There are some noticeable differences in characteristics between the two, due to climate, soil and production techniques. Pinot Gris tends to be a bit softer, with touches of honey and a smooth feel, while Italian Pinot Grigio is a bit more acidic with bitter almond undertones. Technically, there is also American Pinot Grigio which is most similar to Italian Pinot Grigio, but tends to be a bit less tart and more fruit-forward.
Similarly, Pinot Blanc and Pinot Bianco are one and the same as well; Pinot Bianco is the Italian name. Just as with Pinot Gris and Grigio, French Pinot Blanc and Italian Pinot Bianco produce markedly different wines.
The French versions from Alsace are musky and creamy-textured whereas those from Italy have livelier acidity, with pear or even soft citrus flavours. American Pinot Blancs are usually made in the French style, as the name suggests. Pinot Blancs pairs well with cheese-based dishes; Pinot Bianco goes nicely with light foods like chicken breasts or flaky white fish in a simple sauce.
Both the red and white grape are referred to as Pinot because the grape clusters resemble the shape of pine cones. The latter half of their name refers to the colour of the grapes. Pinot Noir is a rather dark skinned grape, Pinot Gris are considered to have a gray coloured skin, and Pinot Blanc is considered to be is often a mix of bronze, green and pink grapes within the same bunch.
Pinot Blanc/Bianco and Pinot Gris/Grigio are colour mutations from Pinot Noir in which they lack pigment, producing the lighter grapes and fruitier wines. Pinot Blanc/Bianco has the least amount of anthocyanin.
The juices of all the Pinots are clear, but Pinot Noir is allowed to remain with its skin for a period of time which gives it its red colour. Pinot Blanc/Bianco and Pinot Gris/Grigio on the other hand are not left with the skin, therefore creating a white wine.
With respect to taste, Pinot Grigio is noted for pronounced, often quite high, crisp and bold acidity. Pinot Gris and American Pinot Grigio have softer, medium levels of acidity but it is still very present.
Aged, Pinot Gris/Grigio will tend to showcase a bit more acidity and structure than Pinot Blanc/Bianco. Pinot Blanc has a rounder expression. It’s actually among the regular, daily whites consumed in Alsace. Unlike the often brighter fruit flavours found in some Pinot Grigio, Pinot Blanc can tend towards apple and even some smoky flavours; it can also be oaked for a bit more richness.
Pinot Blanc is very versatile. It is used in still wines, sweet, and sparkling wine. In northwestern Italy, Pinot Bianco is also used in Franciacorta, which is an Italian sparkling wine. It’s also a major component in Crémant d’Alsace.
Pinot Noir is semi-acidic, though because it is a red wine, the acidity is a bit less noticeable. It is a light bodied red wine with flavour notes of red berries, cherries, and vanilla. When aged there may be hints of vanilla and caramel accents. Clove, licorice, and even smokier tobacco are present in some varieties.
When pairing with food, Pinot Noir compliments light meats such as chicken and fattier fish like salmon. Most Pinot Gris wines have a medium body and crispness, allowing them to pair well with light seafood dishes.
Tannins provide an astringent, drying sensation and also add texture to the wine. For red wine, Pinot Noir is rather light in tannins, and being white wine, Pinot Grigio, Pinot Gris and Pinot Blanc are inherently low in tannins.
Both Pinot Noir and Pinot Grigio tend to be produced as dry wines. Pinot Gris, due to light touches of honey notes, tends to have a touch of sweetness, which can even be considered as slightly off-dry. Pinot Blanc has its own taste spectrum, either rich (when oaked) or lighter and more neutral in the Pinot Grigio way, but usually with more fleshiness and lower acidity.
In summary, when compared, there are a number of differences, but also a few similarities between Pinot Noir, Pinot Gris/Grigio or Pinot Blanc/Bianca. They all tend to be light; refreshing wines with distinct acidity, but can also be more complex and smoother, depending on climate.