Achieving tropical fruit aroma in white wines: from winemaking to consumer acceptance.

Summary – Final Report

The overall goal of this project is to produce Chardonnay wines with increased tropical fruit aroma perception.  In a previous study developed by Dr. Elizabeth Tomasino’s research group, we found that wines with higher concentrations of fermentation esters and volatile thiols imparted more intense tropical fruit aroma nuances.  Therefore, in this project specific winemaking processes (skin contact, β-lyase addition, and two fermentation gradient temperature regimes) were performed with the intent to either increase or decrease these aromas in the wine.  The first two processes (skin contact and β-lyase addition) are known for increasing volatile thiol concentrations in wine.  The latter (fermentation temperature) is expected to increase thiol concentrations and preserve fermentation esters.

In both micro ferments and larger research scale ferments the Skin contact and combination of skin contact and fermentation gradient resulted in wines with higher concentrations of esters and thiols.  Descriptive analysis (DA) showed that SC was significantly different from both FG and SCFG.  SC presented the most tropical fruit aromas, SCFG presented more stone fruit, and FG presented more honey and lemon/lime.  Liking, using a 7-point Likert scale, showed there was not a significant difference between treatments.  Emotional response, using a 5-point Rate-All-That-Apply (RATA) scale, showed significant differences for ‘calm’ and ‘disgusted’ emotions.  Although using Multiple factor analysis to investigate all the data it was shown that liking was associated with positive emotions which were also associated with tropical fruit aromas.

Together this research shows that skin contact and a fermentation temperature gradient have a positive effect on tropical aroma in Chardonnay wines.  Understanding the link between wine processing and quality and consumer desires is important as wine is subjected to different environmental conditions each year, and consistency can be difficult to achieve.  These conditions of winemaking using skin contact and fermentation temperature gradient would be recommendation for winemakers looking for this tropical fruit aroma sensory signature in Chardonnay wines.