AEB proposes Protan Q during the fermentative stage, a quebracho tannin that, even if extracted from wood, has the same chemical structure of a condensed tannin. Its characteristic is to bind directly with grape anthocyanins and tannins with a polymerization process and, when added already during the mashing stage, it subtracts the polyphenolic compounds present in the skin and the berries from the action of the oxygen.