Sensory Evaluation of Syrah and Cabernet Sauvignon Wines: Effects of Harvest Maturity and Prefermentation Soluble Solids

Adjusting the soluble solids of the prefermentation must is a tool by which winemakers can manipulate the flavor profile of a wine. Total soluble solids (TSS) are often modified prior to fermentation by chaptalization or the addition of water, but can be modified also in the vineyard, by allowing the fruit to further mature on the vine. This work presents the effects of harvest maturity and prefermentation TSS on the flavor profile of Cabernet Sauvignon (CS) and Syrah (SY) wines. Fruit from each cultivar was harvested at three approximate maturity targets: 20 Brix (unripe), 24 Brix (ripe), and 28 Brix (overripe). Must from each harvest was first divided, then the TSS was adjusted to match each of the target maturities; for example, portions of the 24 Brix harvest were adjusted to 20 or 28 Brix. Descriptive analysis found 10 attributes that varied significantly among the CS wines and 14 attributes which varied significantly among the SY wines. Harvest maturity primarily impacted the CS aroma profile, as wines produced from unripe fruit showed increased green aroma, but wines produced from ripe/overripe fruit showed increased jammy berries aroma. Increasing the prefermentation TSS of the CS must increased the intensity of bitterness, hotness, and viscosity, but decreased the sourness. The SY wine flavor profile was impacted heavily by increasing the prefermentation TSS, which showed greater intensities of astringency, ethanol aroma, hot mouthfeel, jammy fruit aroma, rose aroma, solvent aroma, ethanol aroma, and viscous mouthfeel. SY fruit maturity significantly affected astringency and earthy aroma, but an interactive effect between harvest maturity and TSS was found for sulfur, cabbage aroma, and bitterness.