Some liquors taste better after years, which is the case for Brandies like Cognac. However, researchers in Spain used ultrasound to speed up the process, cutting it down to just days, according to a study shared by Discover.

When brandies age, the chemical interactions between the spirits and wood casks they mature in determines their colors, scents and tastes. The reaction takes long, with some high-quality brandy taking several years. But researchers wanted to see if ultrasounds could accelerate the aging of brandy.

Previous tests have shown ultrasound waves can help extract chemicals from plant tissues. Ultrasounds are pressure waves with frequencies between 20 kHz and 10 MHz that accelerate extraction processes by causing tissue rupture and improving the extraction of intracellular substances into the solvent by cavitation forces.

Scientists flowed distilled brandy on a bed of American oak chips. As it filtered past the wooden chips, researchers blasted it with ultrasound waves for days. After only three days of ultrasound shots, the spirits were similar to brandies that have been aged for years.

“Obtaining, in three days, a spirit with characteristics near to two-years-aged brandies was something really unexpected for us,” the study’s co-author Valme García told Discover.

For better results, scientists kept the aging liquor in a dark room, at room temperature and by increasing the amount of oak chips.

The taste was well-received by eight judges, including some of the researchers.

“They tasted surprisingly well, with good fruity and sweet flavors and a high aromatic intensity,” said García, who is a professor at the University of Cádiz in Spain.

However, researchers note the liquor shot by ultrasound waves aren’t technically brandies, since European law says only spirits aged in oak casks can be labeled as brandies.

Researchers will test wines next. The detailed findings for the study on brandies will be published in May in the journal Ultrasonics Sonochemistry .