“Oxygen is the greatest enemy of wine” according to Louis Pasteur, the father of modern microbiology. However, there are ways to defeat this enemy, extending the longevity of wine and preserving its flavours. To discover how to achieve this, we need to take a look at the role of oxygen in the production and storage of wine.
Oxygen in wine: pros and cons
In the traditional process, wine mixes with oxygen in the bottle, which has both advantages and disadvantages. The major disadvantage is that oxygen rapidly accelerates the aging process, leading to the deterioration of the wine’s flavours and changes in the wine’s colour. However, some oxygen is needed to fully develop the wine’s flavours.
So, how can we get the advantages of oxygen, without the disadvantages? The solution is potassium metabisulfite.
What is potassium metabisulfite?
Potassium metabisulfite, also known as the food additive E224 or potassium pyrosulfate, is a food preservative which preserves the natural colour of food and protect against bacteria.
The additive is produced from potassium hydroxide (KOH) or potassium carbonate (K2CO3), both potassium derivatives manufactured by Vynova. KOH and K2CO3 find their origin in an electrochemical process involving potassium chloride (KCl), a salt that naturally occurs in the earth’s crust and is widely used in the feed and fertilizer industry.
While it is sometimes used interchangeably with sodium metabisulfite, potassium metabisulfite is usually preferred for different reasons. Firstly, potassium occurs naturally in the human body, in nature and is key for growth and life. Secondly, the use of potassium metabisulfite in food products enables a strong reduction of their sodium content. In addition, the substance is easily assimilated by the human body.
Potassium metabisulfite in wine
In wine making, potassium metabisulfite acts as an antioxidant, removing all the oxygen suspended in the wine, which slows down aging. Natural cork closures enable micro-oxygenation by allowing tiny amounts of oxygen back into the wine so flavours can reach their potential.
In addition to preventing flavours from deteriorating, potassium metabisulfite made from Vynova potassium hydroxide (KOH) or potassium carbonate (K2CO3), preserves the colour of the wine, preventing white wines from turning golden brown or red wines from turning orange and then brown.
How much potassium metabisulfite do you need?
It can be complicated to work out how much potassium metabisulfite to add to your wine. On the one hand, it needs to be enough to inhibit most of the unwanted bacteria, while on the other hand the amount shouldn’t hinder the cultured yeast needed for fermentation. Plus, some countries have restrictions on how much sulphur dioxide (SO2) wines are allowed to contain, which further complicates calculations.
Furthermore, you should only add a small amount to start as it is not easy to remove potassium metabisulfite after it has been added. In fact, if you add too much, there is no chemical way to solve this issue, the only remedy is to give it time to dissipate.
Other uses of potassium metabisulfite
Potassium metabisulfite made from Vynova potassium derivatives has many uses across the food, textile, metal and film industries. Some of these uses include:
- Preserving lemon juice and pickles;
- Preserving fruits as part of the canning or dehydration process;
- Preserving the taste of dehydrated foods to make them more palatable;
- Bleaching agent in coconut cream;
- Stabilising in the brewing industry to inhibit the growth of wild bacteria and fungi;
- Neutralising monochloramine from tap water;
- Dyeing and printing for textiles;
- Precipitating gold from solution in aqua regia (as an alternative to sodium sulfite);
- Developing solutions for photographs.
Vynova is a leading European supplier of potassium derivatives with manufacturing sites in Belgium and France. Our potassium derivatives are used in numerous applications that benefit health and improve our quality of life – like the production of potassium metabisulfite. Find out more about our potassium derivatives portfolio from Vynova or contact one of our sales representatives here.