Balancing phenolic extractability and astringency in high-tannin cultivars through viticultural and oenological interventions

This study evaluates the effectiveness of combined viticultural and oenological practices in managing the high phenolic content and sensory aggression of the Mandilaria grape variety. To optimize the balance between extractability and palatability, the effects of total leaf removal (TLR) and no leaf removal (NLR), post-harvest dehydration, and selective seed extraction (SE) were investigated during vinification. Chemical analysis and sensory evaluation by a trained panel revealed that while leaf removal and dehydration significantly enhanced anthocyanin and total phenolic concentrations, they concurrently led to the highest scores for astringency and bitterness. In contrast, seed extraction effectively mitigated these attributes, however resulted in a less structured profile. The results show that total leaf removal combined with reduced seed extraction is the best-balanced protocol. This approach takes advantage of the higher phenolic potential created by canopy management, while improving the wine’s mouthfeel by limiting harsh tannins from the seeds. These findings suggest that high-tannin indigenous grape varieties need specific winemaking adjustments so that the wine structure better matches modern consumer preferences for balance and sensory harmony.