Carbonic Maceration in Norton (2017)

This study examines the impact of different winemaking styles on resulting Norton wine. Norton grapes were harvested over two days, and on the first day whole cluster, undamaged grapes were placed into a CO2-purged stainless steel tank with dry 71B yeast on the bottom (this yeast promotes ester formation) while on the second day grapes were destemmed and crushed into multiple T bins. This carbonic maceration tank was gassed with carbon dioxide daily throughout the maceration (approximately 17 days) and held at 65°F. The grapes were then pressed on November 6, and the press fraction was separated, inoculated, and fermented to dryness. The other treatment was punched down twice per day in T Bin throughout fermentation, and the T bins were inoculated with a mix of Lalvin C and Clos yeasts. The T Bins were pressed off on November 3. The carbonic maceration wine has higher alcohol, pH, and VA, with lower TA and lactic acid. The carbonic maceration wine has higher color and phenolic parameters, except for catechin. In sensory analysis, 58% of judges were able to correctly distinguish the wines, suggesting that the wines were significantly different (p<0.01). People who were able to distinguish the wines tended to prefer the carbonic maceration wine. There was a strong trend for the carbonic maceration wine to have higher Body than the traditional fermentation wine. There was a slight tendency for the carbonic maceration wine to have higher Ester Intensity. More studies should be performed on carbonic maceration in Norton and other non-vinifera grape varieties. Additionally, more studies should examine the evolution of aroma and flavor of these wines over time, and how this impacts overall consumer preference.

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