Smaller berries = better skin to fruit ratio = more tannin.(Warmer years produce small berries.) Petit Verdot and Cabernet Sauvignon have a thick skin and can extract the lot of tannins. Wine Tasting is fun so don't make it a complicated, scientific campaign. https://objectstorage.ap-singapore-1.oraclecloud.com/p/ma22LqDE6OsTBOCMbGB6gasf76TxaJbkvL2g8LJ3w-6SVS-HwqgK2m9fu9QBe5fP/n/axqjqojndoew/b/Ruou-tay/o/13RuouJohnnieWalkerGoldLabelvatamquantrongcuaviectuanthudotuoihopphap.docx.html