It turns out there might be a science behind producing high-quality pinot noir. Native to France, the grapes used to make the famous wine are relatively thick-skinned and highly sensitive to their environment. They grow best in climates with warm days and cool evenings. Because of the grape’s sensitivity, growers have a hard time knowing when to harvest them. Recently, researchers at Oregon State University have taken a more in-depth analysis to understand how the grapes’ aroma profile changes as they ripen.

It has been known since the 1920s that the aroma of grapes increases as the fruit matures. It’s also an important factor in determining the eventual taste of the wine. Frederic T. Bioletti, a scientist who pioneered grape-growing in California, wrote, “The value of allowing most varieties to mature beyond the stage at which the sweetness is sufficient is the increase of aroma.” In 1993, J.C. Crouzet, a chemist at University of Montpellier in France, expressed how searching for wine aromas and ways to “increase the good ones could improve the quality of wine.” “Aromas come out naturally in aging, but we want to accelerate that process,” he told science writer Richard Lipkin.

Now, researchers have identified four main compounds that are consistently found in more mature grapes. This information can help growers figure out the best time to harvest their grapes. Of the four compounds identified, vanillin—the compound that contributes to the distinct flavor of vanilla—probably sounds the most familiar. Another, β-damascenone, has a floral odor and a woody flavor. The aroma of 4-vinylguaiacol is similar to that of apples, spices, and cloves. The last compound identified, 4-vinylphenol, has a somewhat medicinal aroma. 

While this new information is useful for wine-makers, you can also whip out this new information to impress your date, or your friends at the next dinner party.