Researchers produce cachaça of similar quality to 12-year-old whisky

Popular beverage distilled twice to remove impurities and aged for two years in new French oak casks.

By Karina Toledo

Agência FAPESP – Research performed at the University of São Paulo’s Luiz de Queiroz College of Agriculture (ESALQ-USP) in Brazil shows that cachaça that is comparable to good whisky or brandy in terms of purity and the complexity of the aromas and flavors can be obtained via suitable production methods.

Cachaça is made from sugarcane juice and is a popular distilled alcoholic beverage in Brazil.

In addition to being submitted to a double distillation process, the product developed at ESALQ’s Cachaça Technology & Quality Laboratory on its Piracicaba campus in São Paulo State has another special quality: it is aged in new oak barrels imported from France.

“When you age distilled spirits, approximately 60% of the flavor comes from the wood. The other 40% depends on how the spirits are distilled and fermented, and on the raw material. So the production process influences final quality much more than the raw material,” said André Ricardo Alcarde, coordinator of the research project supported by FAPESP.

According to Alcarde, the compounds released by the wood during the aging process, such as vanillin, enhance the sensory qualities of the spirit. However, each time a cask is used, the extraction of these compounds takes longer and is less homogeneous.

“Oak is not native to Brazil, and imported oak is expensive. Moreover, our laws contain no rules on the aging of cachaça. Many producers use old barrels that have already been extensively used to make wine or whisky,” Alcarde said.

Some producers of cachaça use casks made from tropical wood species. There are also many cachaça brands that are not aged at all.

In the case of Scotch whisky, Alcarde explained, the law requires aging for at least three years in oak, although the casks do not have to be new (first use or first fill). In the United States, bourbon must be aged for at least two years in new casks before it can be sold.

“We set out to see how cachaça would behave when aged in new oak barrels, a procedure not performed in Brazil,” Alcarde said.

The study was conducted as part of Aline Marques Bortoletto’s PhD research, with a grant from FAPESP. It involved the installation of a distillery in the laboratory headed by Alcarde at ESALQ.

“Generally speaking, the cachaça produced in Brazil is distilled only once. However, we needed a beverage produced by as sophisticated a process as internationally recognized whisky or brandy,” Alcarde said.

Double distillation, he explained, eliminates undesirable compounds, such as copper, some aldehydes that can cause headaches, and ethyl carbamate, a potentially carcinogenic substance. It also eliminates certain types of organic acids that are responsible for a burning sensation in the throat.

“Almost 99% of the ethyl carbamate was removed by double distilling,” Alcarde said. “This procedure makes the final product much purer. It has the right alcohol content and is less hazardous to public health.”

Aging markers

Once the distillation process was completed, a portion of the cachaça was placed in 225-liter oak barrels and the remainder was placed in glass containers to serve as the control.

As explained by Bortoletto, the barrel interiors are toasted before filling to increase the volume of aromatic compounds released. “French oak is more expensive than American oak because the trees take longer to grow. We tested the difference between them and found the aromatic profile of French oak to be superior,” she said.

Every month for two years the researchers analyzed both samples to determine the concentrations of 11 chemical compounds that are considered markers of aging. Using a technique known as liquid chromatography, they measured the concentrations of gallic acid, ellagic acid, sinapaldehyde, syringaldehyde, vanillin, coniferaldehyde, vanillic acid, syringic acid, guaiacol, furfural and hydroxymethylfurfural.

“Except for furfural and hydroxymethylfurfural, which can derive from fermentation and distillation but are rarely present in non-aged beverages, all the compounds come solely from the barrel wood,” Alcarde said.

After 18 months of aging, the ratios of the compounds observed in the aged cachaça were equivalent to the ratios described in the literature for 12-year-old whisky and, in the case of some substances, even higher.

Although sensory analysis was not part of the project, from the chemical standpoint, the findings show that the quality of the cachaça aged in new oak barrels is equivalent to the quality of internationally recognized distilled beverages, according to the researcher. “Of course, it would be a product that would sell for a similar price to good whisky or brandy,” Alcarde said. “This cachaça appeals to a different type of consumer, but a market undoubtedly exists for this beverage.”