Scientists from the University of Seville, Spain, have developed a method of finger-printing champagne, cava, and other wines to prevent cheaper products being passed off as the more expensive varieties.
A recent article in New Scientist magazine said that tests were 100 per cent accurate in determining which of 35 samples were cava and which were champagne.
Atomic absorption spectrometry was used to measure the concentrations of 16 trace metals in the champagne and cava. The results showed that nine of these could be used to give the wines a unique fingerprint that was different in the case of cava and champagne.
A commercial statistical programme called SIMCA was used for this purpose. Champagne, for example, contained 0.6 mg/l of zinc, roughly twice the amount found in cava. Cava, on the other hand, had 0.7 mg/litre of strontium, which was twice the level in champagne.
The trace metals are taken up from the soil where the grapes are grown and soils from different regions have differing complex mixtures of trace metals. Cava is produced from grapes grown in the Penedés region of northeastern Spain, while champagne is produced from grapes grown in the Champagne region of France. It is the differences in the soils that is thought to give wines their character.
The same method could be used to fingerprint many other wines to prevent fraud, such as the sale of table wines like Rioja or adding grapes from outside the designated areas for wines labelled as 'appellation controlée'.
It is thought that three quarters of 'Italian' wine sold in the US is not Italian, and it is estimated that up to 10 million pound's worth of counterfeit wine is sold annually across the world. This is the latest example of champagne makers turning to technology to improve their product. Scientists are still working on ways to perfect the bubbles, which according to experts are the key to the drink's flavour and aroma.
And the smaller the bubbles, the better, according to researchers at the university of Reims in the heart of champagne territory in France.
The reason smaller bubbles make better champagne is essentially because there are more bubbles available to release the flavour and aroma. The little bubbles pick up flavour and aroma molecules during their ascent, pulling them along until the bubbles literally explode onto the surface of the liquid, creating the sensory 'fireworks' that are generally associated with a good tasting, refreshing champagne.
An excessive amount of carbon dioxide is the main factor responsible for bubble growth in carbonated beverages, whether produced naturally via fermentation or added artificially. But other factors also play a role in bubble formation, including the degree of diffusion of carbon dioxide within the liquid.
In order to test the extent to which diffusion influences bubble formation, Gérard Liger-Belair, an associate professor at Reims university, measured carbon dioxide concentrations inside equal quantities of five different beverages: champagne, sparkling wine, beer, soda and carbonated water. He found that even though champagne and its close relative, sparkling wine, had about the same diffusion measurement for carbon dioxide, their bubble sizes were significantly different.
Contrary to expectations, the diffusion of the carbon dioxide was not the main factor determining bubble size in champagne, although it did play a major role in the formation of bubbles in the other beverages, said Liger-Belair.
Based on this study, Liger-Belair claims that other chemical components that are dispersed throughout champagne, including dissolved salts, carbohydrates, and minerals, play a bigger role than previously believed in the formation of its uniquely small bubbles.