Prior to the taste test, the researchers passed out short questionnaires to determine the involvement in the wine industry of 330 participants at wine-tasting events in Ontario. Based on the answers to the questionnaire, they divided the people into two groups: wine consumers and wine experts. Approximately 110 of the participants indicated that they were professional winemakers, wine writers, liquor control agents and wine judges and were classified as wine experts. The researchers classified all the other participants as non-experts.

"Statistically, the two groups were very different in how they tasted our bitter probe compound," said Hayes.

Hayes said that previous studies have shown that biological factors may explain the acute taste of experts. Many wine experts may be drawn to careers in the wine industry based on their enhanced ability to taste. While learning plays a role in their expertise and other factors matter, such as how they communicate their thoughts and opinions on wines, some wine experts may have an innate advantage in learning to discern small differences in wine.

"It's not just learning," said Hayes. "Experts also appear to differ at a biological level."