Microoxygenation

Micro-oxygenation is a process used in winemaking to introduce oxygen into wine in a controlled manner. Developed in 1991 by Patrick DuCournau, working with the exceptionally tannic grape Tannat in Madiran, the process gained usage in modern winemaking following the 1996 authorization by the European Commission. Today the technique is widely employed in Bordeaux as well as at least 11 different countries, including the United States and Chile.^[1]

Process

The process of micro-oxygenation involves a large two chamber device with valves interconnected to a tank of oxygen. In the first chamber the oxygen is calibrated to match the volume of the wine. In the second chamber the oxygen is injected into the wine through a porous ceramic stone located at the bottom of the chamber. The dosage is controlled and can range anywhere from .75 to 3 cubic centimetre per liter of wine. The process normally occurs in multiple treatments that can last anywhere from one or two treatments during the early stages of fermentation (to help avoid stuck fermentation) to a more prolonged treatment during the maturation period that can last four to eight months.^[1]

Benefits

The exposure of wine to oxygen in limited quantities can be beneficial to the wine. There needs to be a balance where too much oxygen can lead to oxidation and too little can lead to reduction and the ensuing wine faults. In oak barrel aging, the natural properties of the wood allows for a gentle aeration of the wine to occur over a prolonged period. This aids in the polymerization of tannin into larger molecules, which are perceived on the palate as softer. The process of micro-oxygenation aims to mimic the effects of slow barrel maturation within a shorter period and for less of the long-term cost associated with oak barrels.^[1] It also enables more control over this process, as opposed to barely observing it in such natural material containers as barrels.

During fermentation, the added oxygen can help maintain the viability of the yeast to minimize the risk of stuck fermentation and the production of undesirable sulfides. After fermentation it can aid in the clarification and stabilization of the wine without resorting to the use of fining agents.^[1]

References

1. ^ ^{a b c d} J. Robinson (ed) "The Oxford Companion to Wine" Third Edition pg 442-443 Oxford University Press 2006 ISBN 0198609906