Astringency wine aging

Indeed, after a maturation period of 18 months, no significant differences were seen between the wines obtained without the yeast inoculums, either if they were aged in vinsantaia or at a constant temperature of 18 °C, except for the honey character and the color intensity. Similarly, also inside the cluster of wines obtained with both the yeast inoculum and the addition of madre there were no differences found in the perception of individual sensory attributes. However, the wines from the yeast-inoculated fermentation with the addition of madre were perceived to be more acidic, astringent, bitter, and viscous than the non-inoculated wines when they were aged in the cellar at constant temperature (18 °C). In contrast, there were no significant differences among the wines aged under the traditional conditions (vinsantaia). 

D.3.5 Changes in Tannin Composition and Astringency During Wine Aging.556... 

Wine aging involves a complex and little understood series of chemical reactions which are perceived by the consumer as an increase in flavor complexity, a shift from a bright red or red-purple associated with young red wines to a tawny red hue associated with well-aged red wines, and decrease in astringency. 

A problem common to many wineries in this area is an overabundance of new or almost new wood cooperage. It is often not possible to allow the wines to remain in wood to achieve the level of maturity desired by the winemaker. Rather, it is necessary to remove the wine prior to it becoming too astringent and having too predominant an oak aroma. In lieu of a long wood aging cycle, a number of wineries are bottle aging their wines for an extended period of time prior to release. 

Although irradiation of red wine increased the chemical color "age of the Cabernet Sauvignon wines, sensory evaluations found no perceivable difference in color due to irradiation at the dose rates used in this study. Additionally, irradiation did not decrease astringency of the wines. Due to the adverse effect of the 2.4 KGy dose on flavor and aroma attributes, use of higher dose rates to rapid age Cabernet Sauvignon wines does not appear to be feasible. 

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