Uncorking Wine Fraud

The South African wine industry is among the top ten largest in the world, and is also one of the oldest after Europe and the Mediterranean. Wine is one of South Africa’s largest agricultural export products, contributing a significant amount to the South African GDP. With such an opportunity for economic gain, it is no wonder that counterfeit wine has become a global multi-billion-dollar industry. Wine containing the best ingredients, or which is produced by traditional methods, or that originates from a certain geographical region, comes with a higher price tag. This leaves the door wide open for fraudsters to benefit from counterfeiting.

The South African wine industry is among the top ten largest in the world. According to a study by the SA Wine Industry Information & Systems (SAWIS), the contribution of the wine industry to South Africa’s GDP has increased by more than 10% per annum since 2003. With the growing numbers and thirst of global wine consumers, wine fraud has become more prevalent. It is important for producers, wholesalers and consumers to be aware of the different types of adulteration.

What is classified as wine counterfeiting?

• Diluting with water

There are many different ways in which fraudsters can counterfeit wine. Perhaps the oldest form of adulteration is diluting the wine with water. This may be to reduce a wine’s alcohol levels in order to avoid high duties or taxes, or to increase the volume of the wine.

• Re-labelling low-quality wines

Fraudsters have also been known to create labels, corks and other elements of a certain wine in order to pass another wine off as genuine. There have also been cases in which they have refilled empty wine bottles with low-quality wine, recorked the bottles and sold them as new. In China alone it was discovered that 30 000 bottles of counterfeit imported wine were sold every hour. At the end of 2018, the Wine and Spirits Board (WSB) of South Africa were informed of several South African wines believed to have been counterfeited, and the counterfeits sold in China. These wines were sold by pirate companies who were able to obtain authorisation letters, and company registration and trademark certificates. While it is illegal to forge these documents, the reality is that it is happening on a massive scale. According to WSB secretary Olivia Poonah, consumers are willing to pay more for international wines compared to Chinese wines, and thus these bootleg companies will do anything to make their product seem authentic. This may cause reputation damage to a company’s brand, and as a result may close off trade with the Chinese market entirely for that company.

• Chaptalisation

Another common way in which wines are adulterated is through chaptalisation. In this process, sugar is added to the extracted grape must before the start of fermentation. Chaptalisation results in higher alcohol content, thereby increasing the value of the wine. Higher alcohol levels ensure that wine is stable for a longer period of time, which is crucial for vintage wines. Chaptalisation is allowed to varying degrees in some countries, but is illegal in South Africa. The same effect can be achieved by adding alcohol to wine; however, this is completely illegal in all regions.

• Altering the acidity

Correct acidity is something that winemakers strive for. At sufficient levels, the acidity in wines may play several important roles, influencing the stability, ageing and organoleptic characteristics (such as aroma, crispness, freshness, sweetness and fruitiness) of the final product. L-tartaric acid is a natural by-product of the fermentation process, and is the main contributor to acidity in wine. Depending on the maturity of the grapes, the levels of L-tartaric acid may differ: mature grapes produce less L-tartaric acid than grapes that are underdeveloped. This may require the addition of L-tartaric acid during the wine-making process to ensure a desirable product. This process is allowed, but is regulated by the International Code of Oenological Practices, with only L-tartaric acid sourced from grapes permitted. The addition of other forms of L-tartaric acid to wine, such as those made from fossil fuels or extracted from certain plants, is illegal.

• Methanol addition

One of the most dangerous forms of wine fraud is the addition of methanol. Methanol is produced naturally before and during the fermentation process, and is more prevalent in red wine due to the longer grape-skin contact time. Methanol may be added to wine to increase sweetness; however, at high levels it is a toxic chemical, and is strictly regulated across the globe. In May 2020 in Mexico, at least 35 people died after drinking alcohol laced with methanol. South African regulations limit methanol levels to 300mg per litre of wine.

• Glycerol addition

During the fermentation process, water, ethanol and glycerol are the most abundant compounds in wine. Glycerol plays a major role in the quality of wine, contributing to the properties of mouthfeel and overall smoothness. Fraudsters often add glycerol – a colourless, odourless syrup – to disguise poor quality wine.

• Carbonation

Methode Cap Classique (MCC) wines may also be subject to fraudulent activity. Traditionally, the bubbles in these wines are created during a second fermentation process in the bottle. South African regulations allow carbon dioxide (CO₂) to be added by direct injection into sparkling wines, but not into MCC wines. MCC wines fetch a higher price, as a result of the in-bottle secondary fermentation step. Fraudsters may label sparkling wines, which are cheaper to produce, as MCC wines.

How to spot counterfeit wines

Due to the worldwide importance of wine and frequent cases of fraud and mislabelling, in recent years there has been growing interest in developing analytical methods to determine the varietal origin of wines with some precision.

• Water addition

Stable isotope ratio analysis can be a very useful tool to uncover the addition of tap water, by looking at the water oxygen isotopes (¹⁸O/¹⁶O). This method is based on the principle that the ¹⁸O/¹⁶O ratio is higher in a fruit juice (in this case, grape juice) and water mixture. 

• Chaptalisation

Stable isotope ratios of the compounds carbon and hydrogen can be analysed to detect added sugars. Any sugars derived from cane, beet, corn syrup or a plant of other origin can be detected, due to each plant having unique ratios.

• Tartaric acid addition

The source of tartaric acid can be determined by using multi-isotope fingerprinting (¹³C/¹²C, ¹⁸O/¹⁶O, ²H/H). The fingerprint of tartaric acid from grapes differs from synthetic tartaric acid and other plant-derived forms.

• Glycerol addition

Glycerol addition can also be detected using stable isotope ratio analysis. Glycerol formed as a natural by-product of the fermentation process has a significantly different carbon isotope ratio (¹³C/¹²C) compared to cheaper glycerol from other plant sources.

• Carbon dioxide injection

The source of carbon dioxide in sparkling wine can be identified using carbon (¹³C/¹²C) stable isotope ratio analysis. If the CO₂ was the result of a second fermentation process, it should reflect the botanical characteristics of the wine. The carbon isotope ratio of injected CO2 differs greatly from that of naturally-produced CO₂.

How consumers can spot relabelled wines

1. Beware of wines that do not exist. Do your research, especially when buying rare or high-end wines, and make sure that the wine being sold was in fact produced that year.
2. Look at the colour of the label. Ultra-white paper was introduced in 1957, and is fluorescent under blue light. If you are buying a wine older than this, it should not have a label made from this kind of paper.
3. Examine your label closely. Fraudsters have developed ways to age new labels so that they appear older. Such techniques include tobacco staining, applying shellac dirt, baking labels in ovens, and even sanding the labels with sandpaper to create certain characteristics.
4. Look at the glue used on your wine label. The white glue used today was introduced from the 1960s; and like the ultra-white paper, it should be fluorescent under blue light. Also be on the look-out for glue stains around the edges, nicks and tears in the label, and glue under capsules. These are all reasons to be suspicious.
5. If you take a look at the wine’s capsule, there should be no creases, thumbprints on wax or residue from a previous closure. Also look out for a recycling logo on the capsule, as this was not common on old wine bottles.

Lastly, check for any wine sediment left on the cork. This is hard to fake, and will often appear glitter-like if it has been faked.

Knowledge is power, and knowing how to identify fraudulent wine is an essential step in preventing and combating fraud.

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