The effects of natural cork, synthetic cork, and screwcap closures on wine consumer perceptions of the
quality of commercial wines bottled for 33 months were examined in two experiments. The first determined that
wine consumers could not detect sensorial differences between Chardonnay and Merlot wine samples sealed with
the three closure types. The second measured if and how consumer wine-quality perceptions changed based on
the type of closure used to seal the wine. Wines were presented twice to the same consumers: first when the closures
were not revealed and second when each wine closure was revealed. For the Chardonnay samples, the knowledge
that the wine was sealed with a natural cork did not significantly affect the liking or quality scores. However, when
participants knew that the sample was bottled with a synthetic cork, the liking score tended to be lower and the
difference was nearly significant, but quality ratings did not change. When participants learned the wine had a
screwcap, both the liking and quality ratings were significantly lower. For the Merlot samples, there was no change
in liking scores for any of the closures, but quality scores for the wine with a natural cork increased significantly