I cannot tell you how many times we hear some wanker spewing ignorant information to impress someone at a tasting room. Occasionally we have heard enough, drank enough or are not being supervised and we engage the afore mentioned wanker.
So what was the response? - Not only do we not, we would never consider using scewcaps, as they choke the wines and do not breath at all. They make the wine all funky and don't allow any aging at all. What he was referring to was post-bottling “reduction,” unpleasant off odors and flavors created by the mix of oxygen and sulfides.
Natural corks have been used to seal wine bottles for about 300 years. The application introduced the concept of “aged wines,” because of cork’s oxygen permeability. So the big problem is that Oxygen ingress is highly variable due to the varied properties of the natural nature of cork. The impact of oxygen transmission rates can significantly affect wine aroma and color which are influenced by oxygen exposure in the bottle. Too much oxygen decreases fruity aromas and increases oxidative aromas. New Zealand’s signature varietal Sauvignon Blanc is one of the most sensitive to oxygen, perhaps explaining the Kiwis’ early adoption of screwcaps. Red wines are less affected.
Bottom line is, get some facts before spreading more misinformation. Casual tasting room staff can be a real deep well of misinformation so please choose them wisely and try to give them a good information book to reference or tell them to maybe say "I don't know".
Happy Tasting Adventures,