Nothing is more complicated and complicated than the relationship between wine and oxygen.

No matter what words you use, "monkey dog friendship" or "water fish fellowship," the relationship between the two cannot be completely explained.

This is because oxygen has both positive and negative aspects for wine.

The changes that occur when wine is affected by oxygen are called "oxidation". Remember when you cut an apple and left it as it was. Not only do apples become more and more brownish and look bad, but when you try to eat them, they become sloppy and lose their freshness.

Similar changes occur in the oxidation of wine. The first is the change in color. White wine is darker in color, and red wine is lighter in color. At this time, a little brown nuance comes out.

The second is that the fresh and fruity scent fades away, giving a flat impression with no features. Some wines make this feature "good", but it's a thorny problem for wines that sell delicate and aromatic, such as Sauvignon Blanc and Riesling.

Surprisingly, oxidation starts at the vineyard-to-vinification stage, and is involved in all stages of the shipment, home and restaurant. Each step will be explained step by step.

If you want an aromatic wine style, you have to be careful about oxidation from the harvest stage.

Among them, night harvest is known as an effective means to stop oxidation. Oxidation is more likely to be promoted at higher temperatures, so if you want to protect your grapes from oxidation, it makes sense to harvest at cool nights. If it is a machine harvest, the speed can be increased, so it is a gold rod for demons. That's why New Zealand's Sauvignon Blanc is often mechanically harvested at night.

In addition, it is also effective to block contact with oxygen by filling an airtight container with carbon dioxide or nitrogen before cooling until it arrives at the winery and before entering the vinification process.

This kind of winemaking that keeps out of contact with oxygen is called "Anaerobic winemaking".

Sulfurous acid (SO2) is generally added to prevent oxidation even during the alcoholic fermentation stage.

Sulfurous acid not only prevents oxidation, but also acts as a preservative to stop the action of unwanted microorganisms in the air, making it an indispensable part of wineries.

The choice of container is important if you want to protect the wine from oxidation during storage. Aging in a stainless steel tank or a concrete tub with an epoxy resin lining can prevent contact with oxygen, resulting in a pure fruit-flavored wine.

On the contrary, there are cases where you want to promote mild oxidation. For example, red wine has a mild and smooth tannin due to the small amount of oxygen during aging. In addition, the aroma of fruits is slightly suppressed, and the aroma of humus and leather appears, adding complex nuances to the wine.

The point here is that the effect of oxygen contact varies greatly depending on the size of the wooden barrel and the storage period. small barrel called 225 liters of barrique used in Bordeaux etc. has a larger contact area with oxygen than barrels of 1500 liters or more called large barrels, so the influence of oxidation is large.

In recent years, a technique called "Micro-Oxygénation" has also been used to rapidly perform mild oxidation. Developed by Patrick Ducourno, it is a technique that literally blows a very small amount of oxygen into an aging wine with something like a straw.

This method also softens young wines, so in Bordeaux, where futures buying called "primeur" is common, it quickly spread.

There are also wines that aim to oxidize and make it "good". A typical example is Sherry's Ororoso, Port's Tony type.

Recently, we have also seen orange wines aimed at intentional oxidation. A little unusual is the Australian fortified wine Razagrain Muscat.

The caramel and toffee-like aromas derived from oxidation give these wines a sense of scale.Fukuiku ((
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It is bringing about.

Even at home, the relationship between wine and oxygen is a double-edged sword.

Have you ever felt the scent of hot spring eggs or sulfur when you opened the wine? This is a phenomenon that occurs when winemaking is extremely anaerobic and is called "reduction". It is one of the unpleasant odors, but if you open it and leave it for a while, it will not bother you. If it's a restaurant, you may want to ask for decanting.

Be careful as oxidation progresses most after unplugging. Oxidation begins rapidly from the moment the lid is opened, whether it is mayonnaise or dressing.

What I want you to do without any special ingenuity is to store it in the refrigerator. Just as it is less painful to cool the grapes at the time of harvest, it is less likely to oxidize when stored in the cold after it becomes wine.

After that, cover it and save it. At this time, you can simply cover it with cork, or you can use a special cap.

By knowing the relationship between oxygen and wine, it is possible to know the aim of the maker, such as whether he wanted to make it aromatic by anaerobic vinification, or whether he was aiming for intentional oxidation.

Knowing the effects of oxygen at home will help you enjoy more wine.