Can wine drinkers tell if screw caps or corks are used?

on 24/09/12 at 7:58 am


To help winemakers determine the best caps for their wine bottles, researchers at UC Davis, are studying the performance – specifically the variability – within different types of closures.

Their goal is to determine whether consumers can taste the difference in wines that are bottled and capped exactly the same – a difference that could be attributed only to variation among each type of wine closure.

The researchers – including a wine chemist, a medical radiologist and a biomedical engineer – are evaluating 600 bottles of Sauvignon Blanc wine, each sealed with one of three different types of closures: natural cork, screw caps or synthetic cork. The study will monitor changes in the wine during aging, culminating in a sensory evaluation to determine if wine experts and consumers can taste the different levels of oxidation that occur in the wine due to variability within each type of closure.

Oxidation, or exposure to oxygen, is the most important factor in wine aging, according to wine chemist Andrew Waterhouse, a professor in the UC Department of Viticulture and Enology. But too much oxidation can cause a loss of color, flavor and aroma.

“Our goal in this study is to determine if individual bottles might be getting a lot more or less oxygen – and therefore aging at different rates – as a result of the variation in the closures used to seal the bottle,” said Waterhouse, who is carrying out the study with UC Davis undergraduate student Jillian Guernsey.