From Micro-ox to Nano-ox

By Cyril Derreumaux

In the early 1990’s Patrick Ducournau started to develop the winemaking technique we now know as “Micro-Oxygenation”. Working with the Tannat Varietal in the Madiran region in South West France, he was trying to create a new winemaking tool to help soften the tannins of his wines during elevage, or wine aging. Experimental by nature, Ducournau developed the technique from scratch and he and his team were instrumental in its proper implementation and development.

Now well established among old and new world wineries, benefits of micro-ox include improved mouthfeel (body and texture), enhanced color stability, increased oxidative stability, and decreased vegetative aroma.

For those not familiar with micro-ox, I usually start with the metaphor of a fire: Fire must have just the right amount of oxygen to thrive. Too little and the fire dies. Too much – and the fire dies. Same for wine maturation. Same for us human too by the way… Isn’t ageing a slow oxidation of our cells?

As an aside, my passion is ultra-endurance rowing so I understand all too well the importance of oxygen, surely the most underrated fuel for our body. We can live without eating for months, we can live without drinking for days, but we can’t live without oxygen for more than a few minutes. Okay, revenons a nos moutons (let’s come back to our sheep), like we say in France…

Ducournau’s technique was initially thought quite radical because oxygen in wine has long been considered as an enemy, something you didn’t want to mess with for fear of oxidation... To reassure his clients, Ducournau invented the term micro-ox, explaining that only micro-amounts of oxygen is introduced, using specific diffusers sparging tiny micro-bubbles. It’s not oxygenation he said, it’s micro-oxygenation!

Oxygen can be introduced at several moments in the winemaking process. It can be used during fermentation, in order to “feed” the yeasts; during phase 1 (or the Structuration phase), which is the period between AF and ML; or during phase 2 (aka the Harmonization phase). The rates of oxygen addition between phase 1 and phase 2 are a 10x ratio. For instance, if you can go up to 35mg/l/m in phase one, your wine would probably be okay to start with a rate of 3.5mg/l/m in phase 2. Phase 2 is what naturally occurs in barrel aging, with low amounts of oxygen intake occurring through the staves and through the bung.
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The key to successful micro-ox is to stay within the wine’s ability to consume oxygen faster than the rate at which it is added to the wine. An innovation that I’m so excited by, I now work for, is The Wine Grenade, a hand held device which releases oxygen through a permeable membrane at a molecular level, rather than the ‘fish tank’ style bubbling technology of diffusers.  This membrane-based or ‘nano-oxygenation’ process does not create bubbles and more closely replicates traditional barrel aging in tanks.
So, from micro-ox to nano-ox, the future is here.

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