The question is, “if it’s the same grape why are some wines called Pinot Gris while others are Pinot Grigio?”
The answer is rather simple: grape variety is just one factor hinting at the ultimate style of a wine. Climate, geology, vineyard and winemaking practices all leave their mark on the final wine just like two pieces of identical steak can be cooked differently and the end results can be vastly different.
Alsace is the home of Pinot Gris in France. Here the tradition is to make big rich wines using Pinot Gris grapes that are harvested late. Instead of immediately pressing the grapes and separate the skin and the juice, they encourage the juice to macerate on the skins for a couple days extracting texture and a little colour. Think of this like a tea bag and water: a one minute brew versus a 5 minute brew while dunking the teabag.
In Italy’s Alto Adige and Friuli regions Pinot Grigio is grown in cooler high altitude sites and picked earlier. The grapes are pressed immediately and there is no skin contact. The fermentation takes place with a controlled low temperature so the aromatic compounds that are created and sustained are different. Here the resulting style is a light bodied, fresh, aromatic wine with a very pale lemon yellow colour.
With Vivace LaStella has always aimed for the Italian style of light, zesty Pinot Grigio.