Extended maceration and cap management impacts on the phenolic, volatile, and sensory profile of merlot wine

The presented study aimed to evaluate the sensory and chemical effects of nine cap management and maceration techniques. Extended maceration (EM) was applied to Vitis vinifera L. cv. Merlot for 1, 2, 4, 6, and 8 weeks. In addition, a punch-down treatment and two submerged cap treatments were also evaluated for a total of nine treatments. Descriptive analysis, polyphenolic measures, basic wine parameters, and volatile analysis were utilized to describe the nine treatments. Extended maceration defined the astringent texture of the resulting wines, while cap management modified the bitter taste and pepper spice aroma. Twenty-seven of 29 measured volatiles showed a significant treatment effect, thus demonstrating the importance of these enological practices on the final volatile profile. A correlation with extended maceration length was shown with 15 of the significant volatile compounds. In particular, the ester profile of the wines showed decreased variability after two weeks of maceration. This study suggests that EM may not be as impactful on astringency as previously thought, due to the fact that EM only significantly affected this attribute after 6 weeks. Additionally, the results of the cap management treatments indicated that bitterness can be modified by punch-down versus pump-over techniques.