Wine oxygen management — the key to fashioning the perfect drop

Since February 2020, the Australian wine sector has experienced two major and totally unexpected events: the COVID-19 pandemic and the introduction of tariffs on Australian wine imports by the Chinese government. While the pandemic didn’t have a significant overall effect on wine sales during the 2019–20 reporting period, longer-term economic downturns in major wine-consuming nations could dampen global demand in the next few years.

With these competitive market pressures in mind — as well as the rising popularity of high-quality wines and the average wine drinker’s increased ability to differentiate between a good and a bad drop — it is now more important than ever for winemakers to ensure that the profile, shelf life and quality of their wine is as good as it can be. The key to this? Wine oxygen management at bottling, and more specifically, keeping oxygen out — which is deemed to be more complex than one may think.

Gas management is key

Wine has been enjoyed for thousands of years and remains one of the world’s most popular alcoholic beverages, but it’s also the most critically judged — particularly by the people who love it the most. As consumers get better at understanding the differences between good and bad wines, every part of the winemaking process becomes more intricate. The newest trend of innovation to improve wine quality is the management of maintaining the right balance of oxygen levels within it, which is said to be the key to developing a wine’s unique profile and prolonging its shelf life so that it is able to improve its taste as it ages.

Discerning winemakers today have worked out a way to identify the main parameters to perfectly manage the measurements of compounds in wine, by differentiating the polyphenols on one side and oxygen on the other. To do this, analysers are used such as the NomaSense O₂ analyser to allow winemakers to measure the oxygen levels in a winery, including oxygen dissolved in wine and in gas phases. Oxygen can be measured at every stage of the winemaking process, including maturity, vinification, aging, closure selection and bottling — but why is it so important?

Why is oxygen management essential?

Keeping oxygen out of wine is like trying to stay dry in a swimming pool — it’s never an easy feat. However, oxygen can have a significant impact on a wine’s style. Low oxygen levels often lead to a wine displaying elevated or fresh fruit attributes, with an absence of developed characteristics such as toasty or honey qualities, with a tendency to form undesirable characters. On the other hand, too much oxygen can lead to subdued fresh fruit characters, the development of stewed and cooked fruits, and the absence of reduced characters and the early onset of undesirable oxidised attributes.

In fact, oxygen’s impact on wine is so dramatic that the same wine exposed to slightly different oxygen levels during and after bottling can result in completely different products entirely. In 2016, a study from the Australian Wine Research Institute looked into the cause of wine defects during the International Wine Challenge, which represented more than 106,000 wines, discovering that roughly 4% of the wines showed considerable defects. When looking at the repetition of these defects, it was apparent that more than 50% came as a result of bad oxygen management, demonstrating just how important it is in determining wine quality and how crucial it is for winemakers to get right.

What are the 3 types of oxygen in a wine bottle?

Although we tend to think of a sealed bottle as a closed environment, this does not mean that once the wine is in the bottle no contact with oxygen will occur. First of all, in the tank, just before starting the typical sequence of bottling operations, the wine itself will contain some dissolved oxygen (DO) — the oxygen that is trapped inside the wine. Also, when the wine is transferred throughout the bottling process, dissolved oxygen in wine can also increase. Secondly, headspace oxygen (HSO), which is the oxygen that is between the wine and the closure, can represent up to 65% of the TPO (total package oxygen) management, meaning the total volume of oxygen in the bottle. TPO can differ between corks and screwcap closures, with screwcaps making up a higher percentage.

When considering the different types of oxygen within a bottle, managing a wine’s shelf life and profile definition is determined by following some key major steps in the process. This includes managing the content of polyphenols, oxygen management before bottling, closure permeability and TPO management. However, the most essential phase to consider is the oxygen level within it, which is something that needs to be measured directly in the cellar.

Solutions for wine oxygen management

To support these practices to better enhance the quality, profile and shelf life of wine through the correct management of oxygen levels, there is a diversity of wine quality solutions tailored for the industry.

Today there is a range of commercial wine packaging options, such as portable analysers, which measure oxygen levels in the winery, including oxygen dissolved in wine and in gas phases. These devices ensure oxygen can be measured at every stage of the winemaking process, and more particularly during the bottling stage, whether you are using bottles or Bag-in-Box to maintain the integrity and quality of the product for consumers. Modern wine quality solutions provide winemakers with decision-support tools and customised services to achieve total wine management and the desired wine style to ensure its long-lasting success, quality, profile and shelf life.

The right oxygen balance pays

Given the amount of time, passion and resources that winemakers put into developing the perfect drop for wine lovers, it pays for both the business bottom line and brand reputation to ensure that all that hard work doesn’t go down the drain once the wine is bottled. So, it is clear that the level of oxygen and rate of oxidisation in wine can amount to serious quality implications. Likewise, the effects of oxygen ingress during the bottling process are critical because they can have an immense influence on wine style, shelf-life determination and the onset of undesirable defects.

The Australian wine industry is one of the most renowned and prolific in the world, and with the region’s wine-drinking consumers and winemakers themselves getting sharper each year, there is now a greater expectation than ever for the highest quality wine to be produced — so getting the right balance is crucial to not only a wine’s lifespan and quality, but your own credibility and finesse as a winemaker.

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