Extended Maceration

In this study we looked at the effect of extended maceration (up to 8 weeks) with daily pumpovers or submerging the cap (also up to 8 weeks) on the sensory and chemical attributes of the resultant Merlot wines.  Chemical measures of polyphenols and basic wine chemistry, along with Descriptive Analysis (DA) comprised three data sets.  Principal component analysis (PCA) applied to the individual data sets discriminated the wines by treatment, with each of the three PCAs capturing 90 – 97%of the treatment variability with in the first three components.  We also used Temporal Dominance of Sensation (TDS) a relatively new sensory technique to evaluate the time component of mouthfeel and taste attributes.

  • Nine descriptive attributes were significantly different.  Maceration was associated with increases in red fruit, bitterness, astringency, drying, and astringent texture, along with a decrease in pepper spice.
  • Descriptive analysis results showed that 8 week extended maceration, whether by submerging the cap (Su8) or with daily pumpovers (Pu8), had similar sensory profiles. Also, the control wines with no extended maceration but with different cap management methods (Po0, Su0 and Punch down (PD0)) were grouped together as similar in profile.
  • The TDS profiles of Po8 and Su8 were different despite each having a similar chemical and descriptive profile, this shows that TDS can pick out sensory nuances that occur over the time course of the wines residence in the mouth that single point methods, such as DA.
  • For all 9 treatments, astringency became the dominant sensation at approximately the same time point.
  • Po0 and PD0 showed a clear temporal progression when compared to the Su0 treatment.
  • Maceration showed a decrease in anthocyanidin concentration that leveled after two weeks, while tannin concentration continued to increase.  The Su0 treatment had the highest anthocyanin measurements.
  • In general, maceration tended to increase compounds associated with apple aroma and decrease fruit/ floral aromas.
  • Maceration gave similar tannin measurements as submerged cap, but a different sensory profile