Smell this!

Once upon a time I was tasting some wine with a newly minted master of wine. The aformentioned maestro poked his proboscis into a glass and pronounced proudly: This is reduced. He said it as though it was a fault; in fact, it was a facet of the wine.

The definition of reduction is a wine that has been deprived of oxygen at the wrong time; reduction can also be said to be the opposite of oxidation. It is a process whereby compounds may lose oxygen atoms. Since wine is fermented by yeast through an anaerobic process (without oxygen), a number of reduced compounds are produced. Reduced sulphur and nitrogen compounds, in the form of hydrogen sulfide and mercaptans (ammonia and amines), are known particularly for the negative characters they impart to wines. Thus, it is possible to have a wine with an unpleasant and undesirable “reduced” character.

In the processes of oxidation and reduction, referred to as redox reactions, various wine components in oxidized or reduced forms react and change from one form to the other. These reactions are always coupled: for oxidation to occur, reduction must also occur.

“Along with a gain or loss of oxygen, a transfer of electrons occurs from one compound to another. Atmospheric oxygen can take a pair of electrons from another compound and cause this compound to be oxidized, and the oxygen atom with its newly acquired electrons is reduced (picks up two extra electrons for each oxygen atom) and becomes O2- such as found in water, H2O, or ethanol, CH3CH2OH.

Thus, a component is oxidized when it loses electrons (or gains oxygen atoms and/or loses hydrogen atoms); it is reduced when it gains electrons (or loses oxygen atoms and/or gains hydrogen atoms). A compound that loses electrons must give them to another compound or atom. This process of transferring electrons from one species to another is the actual basis of a redox reaction.”

The term “reduction”, also used in the sense of “reductive winemaking”, is the current modern standard for making wines, and many contemporary quality-minded winemakers take full advantage of it. In employing this technique, towards the end of alcoholic fermentation on into the ageing process, reduction is considered most desirable state to cultivate. The presence of reduction in these stages of winemaking protects and preserves the acidity and fruit flavours that modern drinkers consider to be a baseline requirement in well made wines. Reduction protects wines from oxidation. Wines that have oxidized (unintentionally or intentionally - many old-styled wines are purposely made in an “oxidative” style - Sherry and Madeira for example) often lack primary fruit flavours, and are often said to be “flat” in the mouth.

Reduction happens when the wine’s tannins become polymerized (small molecules combining to produce large strings or clumps of molecules) and when this transformation has occurred, the conditions favourable for the formation of sulphur compounds like mercaptans and hydrogen sulfide gain ascendance. Essentially, too much reduction creates the conditions for the formation of these stinky compounds. The reduction reaction itself, especially at lower levels, is harmless and olfactorily undetectable.

Rotting vegetation, a just-struck match, egginess, and burnt rubber are the impressions most commonly given during reduction. So what can be done about this? In some cases, absolutely nothing; and in certain instances the level of polymerization is so high that the process cannot be reversed. But in many less serious cases, all that is required is aeration - remember the relationship outlined above - when one compound is reduced, another is oxidized. The stinkiness that results in a wine is the product of the wrong things being reduced and oxidized. In many cases, reductive smells dissipate naturally over time as the bottle remains opened. If you’ve ever heard people talking about funky smells “blowing off”, the reduction of reduction is almost surely to what they were referring. If leaving a bottle open for 15 or 20 minutes doesn’t do the trick, take the next step - decant! The more air one can introduce into the wine, the better chance one has of dissipating any disagreeable aromas.

A Penny For Your Faults

As unpleasant as the sulphury aromas can be, simple aeration through vigorous swirling or decanting will often clear up a light affliction. For more persistent cases, there’s the penny trick. Some bad smells in wine are fatal flaws, but sulphury reductive aromas are relatively easy to banish from your wine by an old trick: simply drop a clean penny (or any copper-coated coin) into the affected wine. The metal in the coin or spoon reacts with the H2S in the wine, quickly converting it into insoluble (and odourless) copper or silver sulfide.

The Reduced Theatre Company

Soif du Mal, Domaine des Foulards Rouges
Bourgueil Les Galichets, Domaine de la Chevalerie
Domaine Matassa Cuvee Romanissa
Cotes du Vendomois, Domaine de Montrieux
Pinot Gris Sans Soufre, Domaine Pierre Frick
Vin de Table Pinot Noir, Thierry Puzelat
Rosso del Contadino, Frank Cornelissen
Cuvee Planet, Domaine du Mazel