Impact of Botrytis cinerea-infected grapes on quality parameters of red wine made from withered grapes

Background and Aims

Modification of important odorants induced by Botrytis cinerea has been reported in dry red wine (Amarone) made from withered grapes, but the impact on wines produced in other regions remains to be elucidated.

Methods and Results

Cabernet Franc grapes from Ontario were dried to 28.0°Brix and fermented with either non-botrytised grapes or a combination of non-botrytised and botrytised grapes (10% infection). The metabolites, including volatile compounds, were analysed and sensory evaluation including consumer preference were assessed. Gluconic acid, glycerol and acetic acid were significantly higher in the B. cinerea wines. Differences in some ethyl esters, isoamyl acetate and hexanol were observed between the Control and botrytised wines. These wines were differentiated by only one sensory attribute. A consumer preference test (n = 153) comparing liking scores of wines from this study to wines previously made from withered grapes fermented with an autochthonous yeast showed no difference in preference.

Conclusions

Inclusion of 10% B. cinerea infection in wines vinified from withered Cabernet Franc grapes makes little chemical or sensory difference, suggesting culling at this infection rate may be unnecessary and does not negatively impact consumer liking.

Significance of the Study

Red wine made from withered grapes may tolerate 10% botrytised fruit without adversely affecting consumer liking.