The Protein-Precipitable Tannins to Iron-Reactive Phenolics ratio (pTAN:IRP) is a useful metric for understanding extraction in skin-macerated wines. Iron-Reactive Phenolics extract readily from grape pulp whereas Protein-Precipitable Tannins require alcohol, temperature, and movements to extract from the skins and seeds. Because of this, high production wines tend to have lower ratios whereas reserve-tier wines generally have higher ratios. pTAN generally account for 50-55% of extractable IRPs in skin-macerated wines. This ratio will fluctuate depending on fruit quality, most notably decreasing with hotter climates. Protein-Precipitable Tannins: Iron-Reactive Phenolics (pTAN:IRPs) 0.5 is heavily extracted typical of powerful wines. For winemakers, these ratios are particularly useful for monitoring adherence to protocols and understanding the performance of vineyards across multiple vintages. We generally don’t place value between higher or lower ratios as a sign of quality, rather, we focus on pTAN:IRP as an indicator of extraction. Lower ratios benefit more delicate wine styles whereas high ratios benefit more concentrated wine styles. We can use the following variables to steer the type of extraction we desire based on the qualities of our fruit. To learn more about the pTAN:IRPs ratio and how it applies to winemaking, become a Bound advising client.
