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Oxidation is the wine equivalent of when a freshly cut apple turns brown over time. When the molecules that make up the wine are exposed to air, they start losing electrons, which changes their properties and makes them smell and taste differently.
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The process known as oxidation and the conversion to vinegar are actually two separate chemical processes. We care about how much air gets in because wine, when exposed to air, starts to oxidize and begins its journey towards salad dressing. There have been arguments for years about whether or not the cork actually lets air in over time, but scientists have determined that the average cork does let in a little air within the first year, but much less after that. Once corked (or screwcapped) very little oxygen gets in, if at all. Technically, the winemaker is usually aiming for less than 1 part per million (PPM) of oxygen in the bottle. The bottling process usually involves displacing all the remaining air after filling a wine bottle with an inert gas such as nitrogen or argon before the cork goes in.
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Wine doesn’t really ever go bad, it just starts to taste nasty to most of us after a while, and eventually becomes vinegar.īut let’s get into a little more depth, shall we?īefore it has been opened, wine exists in its bottle with almost no air contact. So how long does a bottle of wine last once opened? The short answer is: as long as it still tastes good to you. Would you be surprised if I told you I get this question a lot from random people who find out that I know something about wine? What if I told you it was one of the top things that people seem to be searching for when they end up here at my blog? I have no idea why, but since people seem to be asking the question, perhaps they should get an answer.
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