Experienced wine drinkers may be able to tell the difference between cava and Champagne in a blind tasting. But it's now possible to distinguish between the two types of bubbly without even taking a sip, according to an article in the June 16 issue of New Scientist magazine.
Researchers at the University of Seville in Spain reported that they can identify wines from the two regions with 100 percent accuracy by analyzing the levels of trace metals present in the wines. The technique could eventually be used to help fight fraud in the wine industry, for example, by detecting counterfeit versions of wines from appellations in high demand.
The researchers tested 35 samples of sparkling wine -- 18 samples of cava, which is produced in northeastern Spain, and 17 samples of Champagne, which comes only from the Champagne region of France.
Working on the assumption that the trace metal content of grapes would reflect the trace metal content of the soils where they were grown, the researchers used atomic spectrometry -- a means of identifying chemical elements by their unique absorption of electromagnetic radiation -- to measure and compare concentrations of 16 metals in each of the wines.
Initial experiments showed that Champagne contained an average of 0.6 milligrams of zinc per liter, nearly twice the level of zinc in cava, while cava had 0.7 mg of strontium per liter, more than twice the level in Champagne. However, when researchers found that one of the cava samples had lower strontium levels than six samples of Champagne, they realized that measuring levels of just one or two minerals would not be enough to authenticate a wine's regional identity.
Ultimately, researchers compared the concentrations of 16 metals -- a whole profile that essentially serves as a wine's fingerprint. At this level, the tests proved to be 100 percent accurate in telling the difference between wines from the two different regions, said lead researcher Ana Maria Camean.
Similar techniques have been used by U.S. Customs to verify the origin of various agricultural products imported into the country, said Sumer Dugar, director of scientific services for the U.S. Alcohol and Tobacco Tax and Trade Bureau (TTB), which regulates alcohol sales.
The test results add credence to the concept of terroir -- the combination of soil, climate and other factors that make a wine identifiable in taste as being from a specific place. "The work reinforces our idea that Champagne is a unique product from a unique region, and that ultimately location matters when it comes to wine," said Miranda Duncan, spokeswoman for the Office of Champagne USA, which represents the Champagne industry.
The scientists in Spain have not yet done tests to see if the technique is as accurate in distinguishing among other types of wines from other regions.