What is the Effect of Oxidation on My Wine?

What is the Effect of Oxidation on My Wine?

What is the Effect of Oxidation on My Wine?

Any opened bottle of wine that has been left out for an extended period of time may have become somewhat brown and smelled like pennies and vinegar if you’ve ever come back to it. Those are the harmful consequences of oxidation, which is the same process that causes an apple to become brown when sliced or changes the flavor of an avocado.

Oxidation, on the other hand, isn’t necessarily detrimental. In fact, it is a critical component of almost all winemaking processes today.

Many times when you open a bottle of wine, it has already experienced some type of oxidation, whether it was due to contact with air during the winemaking process, maturing in a barrel, or oxygen entering the bottle via the cork after it was sealed.

Oxidation may be responsible for the bland taste of wine that has passed its best-before date, but it can also be the key to unlocking the wide range of flavors that wine grapes can produce when they are properly fermented.

It may be used to soften a tannic red wine, contribute nutty, earthy, and roasted characteristics, and is responsible for the breakdown of main flavors into deeper secondary and tertiary notes in a blend.

When it comes to making a superb wine, controlled oxidation is essential, but what precisely is this process?

Understanding the chemistry of wine oxidation


When a wine is exposed to air, it begins a sequence of chemical processes that transform ethanol (often referred to as alcohol) into acetaldehyde, which is a poisonous substance. This intensifies the color and produces scents and tastes that are often described as grassy, nutty, or apple-like.

Pumping over, racking, and bâttonage (lees stirring) are all techniques that bring oxygen into a glass of wine during the fermentation process.

Oxidative aging is another kind of wine aging, and it includes any wine that has spent time in a porous vessel such as a wood barrel or terracotta amphora (a clay jar). Another regulated method of transforming wine with oxygen over time is bottle aging beneath cork, which is likewise porous.

Oxidation may be responsible for the bland taste of wine that has passed its best-before date, but it can also be the key to unlocking the wide range of flavors that wine grapes can produce when they are properly fermented.


During development, oxygen progressively permeates into the environment, causing reactions to take place. A choice not to “top up” wines that have evaporated in barrels, as well as using new oak barrels rather than old barrels, allows for more air to infiltrate the wine.

When you open a bottle of wine, oxidation happens as well, although more quickly. As a result, the wine is exposed to an atmosphere rich in oxygen (21 percent) and other pollutants (14 percent).

Adding decanting and spinning to the wine will accelerate these reactions, enabling the wine to “open up” and reveal new flavors more rapidly. If the wine has been opened, it will continue to change rapidly, and it can quickly become overly oxidized, even if the cork has been refitted.

What is the Effect of Oxidation on My Wine?

What is a reductive wine, and how does it differ from other types of wines?


Oxidation and reduction are diametrically opposed. Reductive winemaking is evident in several of the wines produced with little exposure to air.

The wine produced in a reductive atmosphere is not difficult to distinguish. As an example, consider a young, unoaked wine that is very fresh and delicious.


Winemaking in hermetic steel tanks is often utilized for the production of numerous white wines, as well as certain reds, and is a technique that is becoming more popular.

This procedure is known as carbonic maceration, and it is characterized by the use of inert carbon dioxide gas to saturate the tank.

In order for complete grape clusters to ferment properly, the process must be stopped. In the world of wine, this process is perhaps most well-known for its use in the manufacture of Beaujolais Nouveau, which is recognized for its very fruity aromatic qualities.

Cal Poly San Luis Obispo’s Dr. Federico Casassa describes wine as a “redox system.” Casassa is an assistant professor of enology who works with Dr. Federico.

As a result, when a chemical or group of compounds is reduced, other groups of compounds are oxidized, and vice versa. In fact, when exposed to a different environment, such as a barrel or an open bottle, a wine made in a reductive manner will frequently age considerably more swiftly..

The distinction between oxidative aging and biological (reductive) aging.


It is also possible to age wines biologically, sometimes known as “aging under flor,” which is a kind of reductive winemaking that is often confused with oxidation. When wine is aged in barrels, a coating of yeast called flore (also known as voile in France) grows on the surface of the wine.

Despite the fact that Flor is typically connected with oxidation owing to its usage in specific kinds of Sherry and nutty tastes, its presence implies the opposite.

The fact that the yeast feeds on oxygen and the wine’s nutrients mean that they really construct a barrier that keeps the wine from being oxidized.

What exactly is Sherry, and is it oxidized or unoxidized?


In order to comprehend Sherry, it is necessary to grasp the distinction between oxidative aging and biological aging. It is so misinterpreted that the term “Sherry-like” is often used to describe oxidation in other wines, which is incorrect.

In fact, a lot of Sherries have been distinguished by a lot of oxidation throughout the years. A good example of this is the wine known as oloroso, which avoids the use of flor and instead relies on 100 percent oxidative aging to give the wine its characteristic deep brown color and richness. Fino Sherry, which contains Manzanilla from Sanlcar, is a naturally aged wine that is shielded from oxygen by the flor that grows on the vines.

The Best Wines Vintages Vineyards In Cote Rotie Rhone Valley.

The World’s Top 7 Wine Bars

3 Pointers For Organizing A Memorable Corporate Event

Wine Pairing With Spicy Food: Professional Advice

Selling Your Wine Collection Through The Online

Color In Red Wine: What It Means And What It Doesn’t

It is not difficult to distinguish between a wine produced in a reductive setting and another.

Consider the flavor of a young, unoaked wine that is very fresh and delicious.
Finos are pale to yellow in color, fully dry, and contain a high level of acid. Their taste character is influenced by autolysis or the flavors that are produced when yeast is broken down.

These may be found in traditional-method sparkling wines, as well as wines that have had a significant amount of lees contact.

It generates nutty and savory overtones that are similar to those produced by oxidation, which further contributes to the misunderstanding.

Biologically aged wines, such as amontillado Sherry, may also turn oxidative with time. It is generated when the protecting flor on a fino Sherry wine dies, allowing air to enter the wine.

Amontillado Sherry is deeper in color and has a distinct combination of characteristics than fino sherry, despite the fact that it is sometimes mislabeled as “medium-dry.”

“By definition, an amontillado Sherry is dry,” explains Andrew Mulligan, Spanish portfolio manager for Skurnik Wines.

“An amontillado Sherry is a dry wine.” Because amontillados are made with no sugar, many mistakenly believe they are sweet. However, despite the fact that it contains less sugar than the typical bottle of California Chardonnay, there is a perceived sweetness.”

Jura’s oxidized white wines are well-known.

The famed oxidative white wines of the Jura area of France are similarly matured biologically, but under significantly different circumstances than those of Spain. The formation of the yeast layer might take many weeks or months, depending on the environment of the location.

The strong flavors of the wines, such as Vin Jaune, are a result of the combination of oxidative winemaking and biological aging.

Joseph Dorbon, who makes wine under his own name in the Arbois appellation, explains that if the voile does not develop on its own, “we will immediately have smells that aren’t pure and tastes that may seriously impair even the structure of the wine.”

“For extended maturing under voile, the most crucial element is to have unoxidized juice with an excellent potential structure and alcohol level.”

Dorbon emphasizes the necessity of using wood in the proper manner throughout the procedure.

“It’s important not to overlook the barrel,” he explains. “An excellent barrel for oxidative aging is an ancient barrel that has acquired over the years the renowned yeasts and bacteria from the wine and ambient air in the winery that is required for the formation of the voile.

“You can’t simply go out and create wonderful oxidative wines,” says the winemaker.

Various varieties of oxidized wines exist.


Other kinds of oxidative wine exist in addition to non-fino Sherries and sous voile wines from the Jura. The majority of them originate from regions where traditional winemaking procedures are followed.

Wines aged in oak barrels to promote oxidation and evaporation, which gives the wine its distinctive nuttiness, are known as tawny Ports.

Madeira: This wine, which is known for its long shelf life, acquires oxidative characteristics as a result of both heating and aging.

Vernaccia di Oristano: A grape planted in Sardinia that is used to make wine in a conventional oxidative solera method or matured in untopped barrels, depending on the kind of wine being made.

In the Czech Republic, Tokaji Szamorodni is an unusual dry form of Tokaji prepared from botrytized grapes that are matured under the influence of yeast. Tokaji with oxidative properties were more frequent in the past.

Additionally, oxidation may be seen in many table wines, albeit there is no clear guideline for identifying them.

Some oxidative whites are bottled in transparent glass on purpose so that the wine’s deeper color would be the most noticeable characteristic. If all else fails, look at the vintage—the older a wine is, the more likely it is to have oxidative qualities.

Instead of dismissing oxidation as a problem, take a closer look at the wine and how it was made. Oxidation is a complicated phenomenon. It has the potential to cause the eventual degradation of wine, but it is also the process through which wines might reach their peak expression.