I’ve been reading The Billionaire’s Vinegar recently, the story about wine unearthed allegedly owned by our third President, Thomas Jefferson.  While I’m only half way through, this “mystery” revolves around the discovery and authenticity of wine bottles with the inscription “Th J” and the intense bidding wars for these prizes unleashed at auction.  You can read my review on the book by clicking here.   What caught my eye was a discussion about the roll that oxygen plays in the maturation or spoiling of wine, in this case, a wine allegedly two hundred year old.  It caused me to pause, reminding me that basic chemistry is so vital to the quality of the end product that we enjoy.

Oxygen was discovered by Joseph Priestly in 1774 when upon burning Mercury Oxide, noted that an odorless gas allowed a candle flame to burn far longer than anticipated.  In 1775, Priestly placed a mouse in a closed jar with oxygen and to his astonishment, it survived 30 minutes and was revived without incident.  Oxygen is the third most abundant element in the universe after hydrogen and helium and constitutes just short of 21% of our atmosphere.  There are two forms of the element that make life possible for all of us.  One is diatomic oxygen (two atoms combined to form O2) and the other O3 or Ozone, a layer high up in the atmosphere that protects us down here from the hazards of ultra violet radiation.  Ironically, Ozone is a pollutant at the surface and can be a component of smog. 

Ok, enough basic chemistry.  Let’s get down to the Dr. Jekyll/Mr. Hyde personality of oxygen during and after wine production.  As a primer, let’s establish the stages of wine production in very simple terms and then parse out how oxygen does its work:  there’s harvest, crushing, pressing (the process of forcing juices from the grapes) and fermentation, storage, bottling and at some delightful point, popping the cork or unscrewing the cap.