Figure 1. WINEXRAY's representative berry profile of Cabernet Sauvignon from the north coast of the United States. (The Future of Winemaking: Honoring the Vision of Professor Roger Boulton, 2022). EXTRACTABLE ANTHOCYANINS (mg/berry) Broadly speaking, great wines have grown where moderate stress leads to higher concentrations of color, tannin, and flavor. The best vineyards have been where phenolic and flavor ripeness coincide. For millennia, the earth’s climate has been stable and wine traditions have slowly formed to best fit that mold. Today, with increasing weather volatility, winemakers need to account for mitigating the risk of extreme environmental stress to preserve their site's equilibrium. Following traditions is no longer a given, it is an ideal. Understanding the behavior of grape and wine phenolics in changing climate conditions is fundamental for making informed decisions. As always, we begin in the vineyard to understand the quality inherent to site. The status quo for quantifying berry ripeness is by Brix, pH, and TA. These fundamental metrics are valuable information for production, but they are also limited in their scope. To gain a deeper understanding, we track the accumulation and decay of extractable anthocyanins as an objective metric of phenolic ripeness, and juxtapose that next to our individual assessment of flavor and tannin development. Figure 1. Anthocyanins prevalent in Vitis vinifera colored by their respective hues. “Phenolic compounds are secondary metabolites. They are not involved in growth and energy metabolism and are usually generated in response to environmental stress (e.g., predation, attack by microorganisms, UV light levels, etc.)” (Harnly et al., 2007). By measuring the accumulation of extractable anthocyanins in grapes, we can understand the environmental conditions that favor their formation. For instance, moderate environmental stress may favor accumulation (43°C/110°F) significantly degrade anthocyanins and tannins alike (WINEXRAY). We value extractable anthocyanins because they play a particularly important role in crafting red wine style by modulating astringency, incorporating flavor, and stabilizing color. Their quality and quantity in grapes are determined by a matrix of growing variables, most notably light, temperature, cultivar, and water. Synthesis Extractable anthocyanins are a profound metric for understanding color potential, grape ripening, and extraction efficiency (when compared to total anthocyanins in wine). The berry is its own biochemical reactor. The soil and vine supply water, sugar, amino acids, minerals, and micronutrients, but the berry is solely responsible for synthesizing all secondary metabolites, including phenolics and flavors (Kennedy, 2002). Anthocyanins consist primarily of free anthocyanin monomers as well as some bound anthocyanin polymers (generally
