Ask Wine Wizard

Micro-Oxygenation on a Small Scale


Zoni Hansen — Manchester, Washington asks,

I went to the most recent Winemaker Conference and there was discussion on the benefits of micro-oxygenation during wine storage. I use glass carboys because larger containers are too heavy. I also like to keep the wine on the fine lees. So, I don’t want to rack every three months. I found an O2 wand with a controller that beer brewers use and was wondering if this could be used sparingly in lieu of a larger HDPE vessel, barrel, or more frequent racking. Here is a link to the one I was looking at:


A brewer’s O2 wand is an interesting tool and one I’m not familiar with personally, though I think I understand the concept. There isn’t much of a description of the item on the given website, but it looks like it’s a metal wand (which can be placed at the bottom of carboys or kegs) and through which oxygen from a cylinder can be metered. It’s tough to tell what kind of oxygenating stone is at the bottom; if it’s a typical “fish tank bubbler” this is not a proper micro-oxygenation stone and will deliver more of what we would call “macro-aeration” of wine, akin to racking from one container to another. 

Micro-oxygenation is something commonly used by people with large tanks. The smaller the container you use in winemaking the greater the ratio of overall lifetime oxygen ingress to wine volume. Barrels (which are naturally porous) and carboys (which sometimes don’t seal completely) typically don’t need any kind of micro-oxygenation work. Racking twice or three times a year using these vessels is sufficient. Once every three months seems excessive to me. Naturally, commercial large-scale winemakers making wine in 50,000-gallon (1,900-hL) stainless steel tanks with small doors and manways need to find ways for oxygen to get into their wines over time. In these cases, micro-oxygenation is a boon and a blessing — and basically a necessity to avoid reductive compounds from rearing their ugly heads. 

My main warning with anything related to oxygen in winemaking is to take extreme caution in avoiding overdoing it. Oxygen can be a wine’s best friend but also its worst enemy. During the early stages of winemaking, yeast need a lot of oxygen to grow and ferment correctly. Young, rough tannins and anthocyanins need a certain amount of oxygen to start to condense into larger molecules and help the aging wine smooth out and develop. Too much oxygen, especially after about three months of age, can accelerate the aging process and, if taken too much to the extreme, can cause premature oxidation and can entirely ruin a wine. 

Not to leave you hanging (because this is such a large topic it’s impossible to cover everything here), I suggest you undertake some further reading before deciding to open up an oxygen salvo on your small clutch of carboys. 

May I recommend this article entitled “Good Oxygen” by Daniel Pambianchi that can be found at: winemakermag.com/article/good-oxygen

Daniel goes into the basics of “macro-” and “micro-”oxygenation in wine. In addition, there’s a great digital audio download available to purchase at winemakermag.com/shop called “Macro-aeration and Micro-oxygenation of Wine”, from the 2009 WineMaker Magazine Conference where Daniel Pambianchi does a deeper dive into a session dealing with these complex and devilishly detailed topics. 

My advice at its most basic is to proceed with caution into the wilds of micro-oxygenation only when you’re sure your situation requires it (it’s not a substitute for racking off of solids, for instance) and when you feel comfortable that your tools of choice won’t blast your wine with so much oxygen as to spoil it.