The high prices of some of these wines mean that they are often counterfeited to scam the unwary

Wine is one of the oldest alcoholic beverages of humanity, in fact, there is archaeological evidence of the existence of this fermented around 7000 BC in an area between the Tigris and Euphrates rivers. At present we can find hundreds of varieties on the market with prices ranging from the most humble to tens of thousands of euros. Unfortunately, the high value of some causes them to be the constant victims of forgeries and hoaxes.

One of the most classic scams is to fill the bottle of a good broth with a low-quality one, what has always been called a carafe. Luckily, more and more research is being done so that we are not given a hoax. Now, a new system of the University of the Basque Country (UPV) wants to detect oenological fraud without the need to uncork the bottle.

The quality of a wine is determined by its organoleptic characteristics: smell, color, and flavor. For this reason, characterizing a product about its aromatic composition is the same as ensuring its cleanliness, way of preparation and packaging, and even avoiding fraud and counterfeits. The truth is that this liquid is one of the most complex alcoholic beverages, with more than 1,000 identified volatile components. This makes detection of fraud by sensory analysis difficult and chemical analysis complex. However, there are several promising analytical approaches.

This liquid is one of the most complex alcoholic beverages, with more than 1,000 volatile components identified

The space in the neck of a bottle of this elixir is made up of the gaseous substances that accumulate between the cork and the wine and constitute a chemical balance until it is opened. The information provided by the components present in that space may be characteristic of the variety, vintage, production method, or designation of origin of the broth. The problem is in reaching that space of the container that still has the cork, without destroying it (to avoid economic losses).

The confidential

The Central Analysis Service of Álava (SCAA-SGIker) of the UPV has designed a simple sampling model, which allows the extraction of wine vapors without the need to remove the cork from the bottles. This tool, together with the measurement technique called Gas Chromatography-Mass Spectrometry (GC-MS), allows to determine the volatile compounds present in the headspace of the bottles and to carry out an approach to the detection of fraud in the oenological world.

The key to analyzing the quality of the wine is in the gaseous substances that accumulate between the cork and the wine

The designed test is capable of extracting a small portion of the gas from the said space of the bottles without uncorking them. It is a device that has a syringe attached to it that imperceptibly perforates the cork, extracts the gas, and allows sealing once removed.

Analytics in triplicate

The analysis of the study has been carried out in triplicate for each of the selected wine bottles, thus guaranteeing the reproducibility of the results. 22 wines were selected (11 Crianza and 11 Young). In total, 20 compounds from these wines were identified, many of which are the same in both aged and young wines. The identified compounds are secondary flavors, mostly esters, ketones, acids, or higher alcohols.

To classify the wines and achieve the main objective of the research, it was necessary to find indicators that distinguish the different types of wines. Thus, depending on the aromatic compounds present in the neck space, the wines could be classified and possible fraud in their vinification and production could be detected.

As a result of the study, it can be observed that young people have a similar chromatographic profile, detecting in all of them two compounds typical of the vinification of young wines (3-Hydroxy-2-Butanone and γ-Butyrolactone). In the case of aging, more efficient yeasts are used and, possibly, the degradation route is different, which is why aged wines do not present these aromas.

The UPV institution defines this new device as “certainly effective in extracting and identifying highly volatile compounds or those with active aromatic activity”, which makes it possible to distinguish between young and aged wines without having to open the bottles. So we can know, without having to uncork the broth, that what we buy is what is labeled, without being surprised, that it could be a millionaire, by drinking a glass.