For tannin levels in wine, the concentration in wine did not reflect the levels measured in fruit. LT/HA made from fruit with low tannins, had a tannin concentration similar to HT/HA, which was made using fruit with a high tannin concentration (Fig. 3B).
The same was observed for LT/LA and HT/LA, which both had low wine tannin levels, but LT/LA was made from fruit with low tannins and HT/LA was made from fruit with a high tannin concentration. The tannin concentration of LT/HA and HT/HA remained higher than LT/LA and HT/LA with aging. While the differences between wines were maintained with aging, an unusual increase in tannin concentration was observed from 12 months to 3 years of wine aging. This might be explained by the associations and dissociations of tannin with aging and the potential role of tannins in colloid formation (Scollary, Pásti, Kállay, Blackman, & Clark, 2012). The formation of colloids and their effect on the ability to measure tannin is unknown and could be an explanation for changes in tannin concentration with aging.