Postmodern Winemaking


Building Structure: The Tool Kit

March 2010
by Clark Smith
So now we’re pregnant. In our first two columns about Postmodern Winemaking, we touched on its history, its general tenets and its usefulness in growing and making age-worthy wines. I explored the role of good colloidal structure in aromatic integration, soulfulness and longevity, and stated the principles necessary for obtaining the ideal building blocks for stable colloidal structure.

If you got hooked by my advice, you’d have committed heavily to an entirely different wine style and way of working. And as I warned you, these practices result in wines that are rather unpleasant in youth. So in this article I will, as promised, chart a path out of these thick woods.

These techniques are not a recipe, and they do not constitute the only path to good structure. For example, years ago I was treated to an understanding of the methods worked out at Dominus Estate to obtain integrative structure, and although it did not touch on my system at any point, it was clear that our goals and our guiding aesthetic were the same. We had simply worked out different paths to similar ends.

My postmodern tool kit includes a suite of new membrane applications I helped develop during the past two decades. Reverse osmosis has proven very handy in obtaining balanced wines of any desired ripeness, whether to remove diluting rainwater or to lower alcohol in rainless climes like parts of California.

Its VA removal capability also provides a valuable backup plan for low-sulfite wine production, and in support of cellar strategies pursuing microbial balance. Ultrafiltration is a powerful new method for managing phenolics and for making concentrates useful for co-extraction during fermentation. These are potent tools demanding elucidation.

But not today. Membranes will have to wait for a dedicated article later on. Here I’ll just deal with the core competencies: oxygenation, lees and the diverse functions of oak.

‘I will fear no tannin’
I learned this mantra from Randall Grahm. In modern winemaking, excessive tannin is viewed as a problem best avoided by careful handling and sorting of fruit, gravity systems, gentle crushing, delicate cap management and low-pressure pressing (if any). When these measures fail, the standard fix is a protein fining treatment that one hopes does not strip too much flavor.

The postmodern view is, I believe, an older one in which tannin is an asset, not a defect. The more, the better. This outlook arises from awareness of structural refinement techniques.

Say you wake up one morning and someone has unloaded a huge pile of bricks on your front lawn. Not a good way to start the day, right? After you simmer down, you hire some guys to haul them away to the dump.

Or if you’re a mason, you put an addition on your house.

Experience with élevage unlocks the possibility of harvesting at true ripeness, when tannins are at their meanest, and permits the winemaker to pursue full extraction and extended maceration without fear of bitterness or astringency. These are culinary skills, not very different from chocolate-making techniques.

Tiny bubbles in the wine
In the last installment, we discussed the elements of vine balance, proper maturity and good extraction necessary to imbue young red wines with the necessary building materials for a structure deep and fine enough to integrate aromatic elements such as oak, vegetal aspects and microbial notes into one coherent and soulful voice.

Such wines will at first exhibit harsh green tannins, closed fruit aromas and reductive off odors. This is a good thing. Like an infant’s temper tantrum, these disagreeable behaviors are signs of intense vitality we can channel toward greatness.

Newly fermented red wines begin their lives with aggressive, coarsely particulate tannins, which are sensed forward in the mouth, just on the tip of the tongue. If kept away from oxygen, they will remain like cocoa powder, with gritty, poorly formed tannins that lack integrative properties and offend the whole palate—defects rather than assets. Such raw undeveloped tannins are the hallmark of the reductive winemaking practices that modern winemaking ushered into France 50 years ago.

One of the worst offenders was the Tannat of Madiran. Here in the late 1980s, a desperate vigneron, Patrick Ducournau, in cooperation with Michel Moutounet at INRA Montpelier, worked out methods for harnessing Tannat’s reductive strength as a force for good. He named his invention microbüllage, later anglicized to “micro-oxygenation.”

By definition, MOx involves continuously dissolving pure oxygen gas into wine at a rate equal to or less than its uptake capacity. Yes, Virginia, wine gobbles up oxygen. And in doing so, it can convert its vitality into structure the same way a blender’s energy whips up a meringue.

Blasting in oxygen in short bursts is not MOx, and it actually has reverse effects—breaking down structure rather than building it—in the same way that blackening a steak is different from simmering a roast.

MOx is just the centerpiece of a whole system of élevage. This French term compares the raising of a wine to the active process of raising a child. The MOx approach to élevage includes a sophisticated knowledge of oak functionalities, press wine blending, lees timing and temperature effects.

School of hard MOx
Even for those with no love for MOx’s creepy high-tech reputation in the luddite press, or those who simply prefer to stick to conventional techniques, experience with oxygenation is essential to a full understanding of the bizarre, paradoxical nature of wine itself. Simultaneous with its structure-enhancing effects, MOx is, in essence, an oxidative titration—a snapshot of a given wine’s reactive vigor.

Anti-oxidative power is a rapidly moving target: different for every wine, and varying as much as a thousand-fold. A burly young Cabernet Sauvignon deprived of oxygen is a bull in a china shop. A tender young Sauvignon Blanc subjected to a young Cabernet’s appetite for oxygen has as much chance as a toddler in an Ultimate Fighting Championship octagon; a couple years after vintage, an extended hang time Cabernet may be just as feeble. Without a grasp of these disparate realms, well-considered cellar stewardship is an illusion at best.

Two decades after Ducournau&rsq uo;s discovery, nobody doubts that micro-oxygenation is here to stay. The outrageous-seeming claims about taming tannins, integrating vegetal aromas, stabilizing color, controlling reduction and replacing or out-doing barrels are now an accepted part of the winemaking fabric. Winemakers increasingly view oxygen the way a carpenter treats a power saw—as a dangerous but essential tool to be treated with care and respect.

The challenge is no longer to prove it, but somehow to do it and do it right. This is no small task. Micro-Ox provides a window onto the weirdness that is wine. Its implementation takes quite a bit of getting used to, almost like moving to some foreign land.

The basics
Enological oxygenation can be divided into five categories:

1. Hyper-oxygenation of juice to remove tannins and browning precursors prior to fermentation.

2. Macro-oxygenation during fermentation to promote yeast health.

3. Post-fermentation micro-oxygenation, performed post-fermentation at a constant low rate.

4. Instantaneous introduction (“clique-age”) to fight reduction, polish structure and promote earlier release.

5. Sulfide treatment through low, slow oxygenation, often in concert with oxygenated lees contact.

The three faces of MOx
Micro-oxygenation practices are further divided into three phases, each with a different purpose. Phase I work, when the wine is at its most responsive, is the central focus of postmodern work, because it takes advantage of the fleeting opportunity to harness the wine’s youthful energy to transform its structure into something stable and refined. As I explained last month, oxygenation behaves homeopathically, initially increasing O2 uptake capacity, paradoxical as that sounds.

Phase I is usually avoided altogether by conventional winemakers, because it requires intensive training and involves substantial risks for the unschooled. It also ties up tanks, increases necessary aging and often causes young wines to show poorly for a time.

When to use micro-oxygenation
Phase II work is done post-ML, just after SO2 addition, to refine and civilize tannins and partially quench reductive strength prior to barreling down. It is also effective for wines that are not destined for barrels, in conjunction with oak alternatives. However, such wines must be given an opportunity to off-gas tanky aromas, a tricky problem MOx does not address.

Phase III is performed after barrel aging, when the wine may have become too delicate to continue in wood but still needs a tannin “haircut.” Commonly, the pithy oak tannins of new barrels take a year or two to begin to extract, and they can disrupt a maturing wine’s harmony at just the wrong time. A couple months in tank at half or a quarter of a barrel equivalent can restore roundness and harmony. Phase III is also employed to knock down reductive strength prior to bottling, particularly in preparation for bottling under screwcaps.

Shopping for equipment
As with a kitchen appliance, picking out MOx equipment begins with identifying your goals. The stove or food processor that’s right for you depends on whether you are Masa’s or McDonald’s.

That said, as winery expenditures go, micro-ox equipment is quite a bargain, topping out at about $2,000 per tank system. My advice is to buy the best. High performance MOx gear is one of the best bargains of any plant investment for increasing quality while also decreasing costs.

MOx work began with stripped-down experimental prototypes. These have proven inadequate for serious full-plant installations, where pennies saved in investment can cost many dollars of inconvenience. Today’s systems enable hyper-ox, macro-ox, micro-ox, clique-age and sulfide treatment, all from the same diffuser. Internet-based control panel displays can link to lab and sensory databases and fixed sensor inputs for temperature, D.O. and so forth, enabling adjustment and troubleshooting from any location including your pocket PC. Still, that initial purchase is usually a high-end small unit on which you can build your skills.

Your key choice is the diffuser. For post-ML Phase II work, just to soften aggressive tannin for early release or to polish the rough edges an average quality oak alternative imparts, many wineries (foolishly, I think) choose a low-end model with a stainless diffuser. Bear in mind that this type of equipment is not suitable for pre-ML Phase I work for structure enhancement, color stabilization and aromatic integration. For these, the tiniest bubble size is critically important. Membrane-type diffusers have the added benefit of providing a built-in continuous bubble-point integrity test.

Most large conventional wineries already have adapted wholesale late-stage MOx. If your intent is to produce clean, affordable wines in a factory setting, you probably know all you need to know about micro-oxygenation. Yes, tanks can replace barrels, and tannins can be softened using even the cheapest MOx equipment on the market.

For you, the big news is that the experimental prototype systems of a decade ago have been replaced by professional plant-integrated systems that interface with your existing process control, lab and sensory databases and place the control panel on your browser instead of atop the catwalk.

Wineries that have turned the corner to postmodern methods generally place a premium on quality over image, and they are able to shift a few marketing dollars to skilled winery labor to ensure that the winery’s credibility resides in every bottle. Any size is possible, even large volumes. Rule No. 1 is stay close to the wine. Rethink your assumptions, trust your senses over your theories, and go with what works. These wineries generally budget for a bit of coaching from an expert in the first couple years at least.

The devil in the details
Setting up for Phase I Micro-Ox involves a fair degree of prior planning and adjustment of standard crush protocols. Treatment is ineffective in cloudy wines or at low temperatures. Suspended particulates such as yeast and grape solids are powerful oxygen scavengers. Fortunately, however, a good diffuser run at 60 mls will often clarify a burly young red in 48 hours. ML suppression is important to maintaining clarity, so SO2 at the crusher is commonly bumped to 45-50 ppm to slow its onset.

It is pointless and dangerous to run oxygen outside the ideal range of 59-65oF. The engine of oxygenative structuring I explained last month (Singleton’s vicinyl diphenol cascade reaction) is extremely temperature sensitive, with reactivity dropping 80% at 50oF. That means a wine can absorb five times as much oxygen at 59oF as it can at 50oF, so a single degree’s difference changes everything in a cellar. Here again, oxygen work dramatically reveals essential information for winemaking in general, explaining, for instance, the common occurrence of volatile acidity in the cold cellars of Burgundy and Oregon.

Unless you have heatable glycol, keeping tanks in the proper range is a challenge. Pumping through heat exchangers doesn’t work very well, as stirring up solids renders treatment ineffective. Drum heater belts are an inexpensive fix which can hold a 4,000 gallon tank 15oF above ambient with 1,000 watts of house current.

The lighter the wine and the further the tannin/color ratio veers from 4 to 1, the trickier MOx treatment becomes. Big Cabernets and Petite Sirahs are easy to work and often beg for it. Pinot Noirs should be avoided by beginners, and even Zinfandels tend to be very tricky. Blending-in press wine is often very useful, and well-selected oak products can supplement deficient wines by providing cofactors, oxygenative phenolics, framing astringency or sweetness.

Driving with your tongue
Ducournau developed a system for monitoring MOx treatment through frequent tasting. Sulfides or aldehyde are the primary indicators to adjust the O2 rate up or down, supplemented by the openness of fruit expression. Tannin evolution is followed from green to hard to firm to round to melted.

I have encountered amazing resistance from Californians to piloting MOx by palate. They want numbers. But the behavior of a wine cannot be reduced to a few instrumental parameters any more than we would wish to be deprived of looking out the windshield while driving our cars. I believe the source of this reluctance is that palate training is sadly lacking in California’s academic institutions.

Despite this reluctance, instrumental parameters such as dissolved oxygen have yet to prove an acceptable substitute for the human palate. I think this is good news. Kurt Vonnegut said, “90% of life is showing up.” Oxygenation forces us to show up for our wines, learn their ways, and discuss and guide their evolution on a frequent, even daily basis. Annoying as it is, this approach inevitably leads to better wines. Get over it.

Please lees me
Finally, I want to touch on the use of lees in building structure. Here again, timing is everything. In Phase I MOx, lees gobble oxygen and suppress phenolic reactivity. They can also adsorb precious anthocyanins (the key to good structure) as well as promoting their enzymatic destruction, with the result that wines dry out and fall apart.

I think of lees like egg yolks in making a soufflé: Initially they must be separated out so a rich, light structure can be created. Just as we whisk egg whites into a meringue, we oxygenate tannins into a mouth-filling, refined presence. But once we have the structure built, we can fold the yolks in for a rich fatness. Lees may be incorporated the same way through frequent stirring. In big wines, this process may actually allow the wine to take up the entire mass of fine lees.

After discarding the gross lees, fine lees may rest on the tank or barrel’s bottom, or they may be held in separate cooperage, where they are stirred and oxygenated until ready for use. Lees must be matched to the wine involved, as Cabernet lees will ruin a Pinot, and Pinot lees will deplete a Cab.

In wines that have dried out, oxygen will only make things worse, but lees can bring such wines back from the brink by coating coarse edges. Lees of the current vintage can prove useful for freshening and softening older wines on the verge of collapse.

Life in micro-hell
Micro-oxygenation’s decade in the cellar has taught us several lessons. First of all, structural MOx work does not tend to hasten the bottling date. In general, wines are strengthened and stabilized, often demanding extra age, but more expressive and better balanced than the same wines untreated.

Plan on investing three to five years. The first year, basic technique. Year two applies this to diverse wines and styles, early blending, and the complexities of oak and lees management. Only then can the winery’s transformation begin, as it grapples with vintage variations and follows bottle evolution over time.

MOx does not lessen our work load. Instead, it pushes us to invest extra time, but with generous dividends in wine quality and learning curve.

It was, to say the least, interesting for me to discover, 30 years into my career, that practically everything I thought I knew was wrong. Keeps you young, I guess. Learning high performance MOx is such a pain in so many ways, you will certainly hate it.

But you’ll love it.

Clark Smith is winemaker for WineSmith and founder of the wine technology firm Vinovation.  He lectures widely on an ancient yet innovative view of American winemaking. To comment on this column, e-mail




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