Tannin and Iron-Reactive Phenolics Content in Red Cold-Hardy Hybrid Grape Tissues throughout Development and Ripening.

Phenolic compounds, especially tannins, are important for red wine quality. Wines made from cold-hardy hybrid grape cultivars have much lower tannin concentrations than wines from grape cultivars. This study assessed the phenolics content of berry tissues of three red cold-hardy hybrid cultivars in comparison to cv.