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. In other words, skill.
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 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 far different from chocolate-making techniques.
TINY BUBBLES IN THE WINE
In the last chapter, I discussed the elements of vine balance, proper maturity, and good extraction necessary to imbue young red wines with the prerequisite materials for building a structure deep and fine enough to integrate aromatic elements such as oak, vegetal aspects, and microbial notes into a coherent, soulful “single voice” capable of imparting distinctive expression of the vineyard’s unique characteristics.
Breaking that chapter as I did may conceal the fact that the copigmentation colloids are not the same colloids that bring about aromatic integration. The former have been shown by Roger Boulton to be composed entirely of anthocyanins and cofactors, both monomeric and present in a one-to-one ratio.1 Cofactors are simply a means for extracting color and some other lovely flavor elements, such as, perhaps, the spicy cinnamic acid derivatives, which are otherwise insoluble.
Newly fermented red wines begin their lives with aggressive, coarsely particulate tannins (I believe these are the copigmentation colloids themselves), which are sensed forward in the mouth, just on the tip of the tongue. We call these “green” tannins in imitation of the French tanin vert. In addition, young red wines often exhibit 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 that we can channel toward greatness.
Copigmentation colloids are unstable and do not remain in wine beyond the first year. Polymerization can occur in either of two directions, depending on the oxygen exposure the wine receives and the skill with which it is administered.
If kept away from oxygen, tannins will remain like cocoa powder—coarse, gritty, poorly formed aggregates that lack integrative properties and offend the entire palate, defects rather than assets. Such raw, undeveloped tannins are the hallmark of the reductive winemaking practices that modern winemaking ushered into France fifty 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 Montpellier, worked out methods for harnessing tannat’s reductive strength as a force for good. He named his invention microbüllage (literally, “micro-bubbling”), which has come into English as “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. Poof—gone! And in doing so, it can convert its vitality into structure the same way a wire whisk whips egg whites up into a meringue. Newborn reds can take up oxygen and build structure a thousand times faster than they will when they are old. It’s not unusual for a new tannat to consume oxygen at one hundred times the rate a barrel supplies.
The main purpose in bringing oxygen to a new red wine is to stabilize color. The red anthocyanin pigments that give wine its hue also have the property of capping tannins, restricting their length by terminating their polymerization. Thanks to Dr. Vern Singleton of UC Davis, we have a pretty good understanding of how this works, and I have devoted the entirety of chapter 6 to his vicinal diphenol cascade reaction, a fascinating mechanism at the heart of wine aging.
It is essential for wine collectors to know the difference between the aggressive tannins that mark deteriorating wines from the equally aggressive tannins found in young wines that will improve.
Nonoxidative polymers are compact and regular but do not efficiently incorporate anthocyanins as “bookends,” with the result that excessive tannin lengthening occurs, leading to aggressive cooperative binding to salivary protein, as depicted in chapter 2, figure 2. The mouthfeel of nonoxidative polymers is initially smooth and low in volume, but as they lengthen they become dry, grainy, and dirty, occurring all over the mouth, including the cheeks and under the tongue. This evolution is commonly associated with browning, oxidative aromas and precipitation. We call these “dry tannins,” from the French tanin sec.
Instead of the long, dirty, dry tannins we get when we withhold oxygen, oxidative polymerization, done right, produces finer colloids composed ideally of short polymers (oligomers) of 5–7 units in length, daisy chains of phenolics with anthocyanins on both ends. Groups of perhaps fifty of these appear to come together to form stable colloids that don’t progress further. These have a fine texture and excellent aromatic integration properties.
Oxidative polymers possess freely rotating linkages and are less compact than are nonoxidative ones, resulting in a larger perceived volume in the mouth and an aggressive hardness, a sheetlike grippiness, entirely on the top of the tongue, that causes it to stick to the roof of the palate (tanin dur, or hard tannin). Over time, as lees proteins and other side reactions coat the tannins, blocking salivary protein interactions, these hard, grippy tannins begin to melt at the back of the tongue, eventually softening completely, producing a velvety impression and a great deal of aromatic integration (tanin fondu, or melted tannin). This softening process may take quite a bit of time. Oxygenated wines are aggressively tannic in youth compared to their untreated counterparts, often coming to resemble them after about two years, after which the MOx wines steadily improve while untreated wines begin to dry out.
Blasting in oxygen in short bursts is not MOx, and actually has reverse effects, breaking down structure rather than building it, in the same way that blackening a steak is different from simmering a pot roast in a slow cooker.
MOx is 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 who simply prefer to stick to conventional techniques, experience with oxygenation is nevertheless 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 capacity. That’s a very useful thing to know, and to know how to influence.
Antioxidative power is a rapidly moving target, different for every wine. 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 octagon—yet 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. (See chapter 7 for the challenges of reductive vigor.)
Two decades after Ducournau’s discovery, nobody doubts that micro-oxygenation is here to stay. Seemingly outrageous claims about taming tannins, integrating vegetal aromas, stabilizing color, controlling reduction, and replacing or outdoing 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. No small task. MOx 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 Three Faces of MOx
Micro-oxygenation