In a new study, scientists at the University of California, Davis have identified the characteristics of the chemical compounds that make some wines taste dry, and it all comes down to tannins.
While past researchers and wine experts have long attributed dryness to tannins in wine, the molecular composition of tannins and how they interact with proteins in saliva have not been well studied.
Dryness or astringency is the sensation you get when drinking certain wines. Tannins interact with proteins in saliva to dry out the mouth.
For this study, researchers extracted tannins from Cabernet Sauvignon and Pinot Noir.
After analyzing the chemical compounds, the researchers found that the drier Cabernet had larger tannins, and when those tannins interacted with saliva, they grouped more salivary proteins together.
Researchers tried to make Pinot sushier by adding Cabernet tannins to fruity wine, but this did not affect the dry feel when trained experts tried the Pinot.
When Cabernet tannins were added to a model wine composed only of ethanol and tartaric acid, experts reported more dryness, suggesting that Pinot's flavors and aromas may have outperformed the new tannins.
The researchers say the findings could help winemakers produce better wines and manage dryness.