Accentuated Cut Edges (ACE): Effects of Skin Fragmentation on the Composition and Sensory Attributes of Pinot noir Wines

Abstract

The phenolic composition, aroma and sensory profiles were evaluated for Pinot noir wines made using four different maceration techniques that modified the floating pomace cap during fermentation: 1. Plunged daily; 2. Reduced skin particle size (accentuated cut edges = ACE); 3. Submerged Cap; and 4. ACE plus submerged cap. Wines were analyzed throughout vinification to assess the phenolic attributes: anthocyanin, tannin, non-bleachable pigments, color density and hue using rapid analytical techniques. At 6 months bottle age (230 days post inoculation) sensory and aroma analyses were conducted on the finished wines. ACE macerated wines were found to have the highest proportion of red color, tannin, non-bleachable pigments, fruit and floral aromas, bitterness and astringency while submerging the pomace cap resulted in a lower concentration of phenolic components than for ACE wines but a significantly higher phenolic content and dark cherry aromas and flavor than control wine. These findings suggest that the employment of either maceration technique has the potential to make a considerable difference to the wine style produced from a given parcel of fruit and ponders the benefits that might be achieved if grape solids were removed early in the ferment. Linear regression analyses were conducted to compare descriptive wine parameters with instrumental phenolic measurements and demonstrated several strong correlations: red color appearance was correlated with both color density (r²=0.95) and non-bleachable pigment (r²=0.95); dark fruit flavor was correlated with both color density (r²=0.85) and non-bleachable pigment (r²=0.85); and astringency was correlated with both tannin (r²=0.97) and non-bleachable pigment (r²=0.87), demonstrating that techniques of rapid chemical analysis were able to provide valuable insights into the sensory properties of the wine and may become useful tools for monitoring the development of the wine during vinification. While submerged cap vinification also increased the tannin and stable pigment profiles of the wine, ACE maceration was found to be significantly more effective and is likely to be more readily adapted for application in commercial wineries.