Scientists have come up with stone-cold proof for what tipplers always knew: that beer tastes best when it’s chilled.

Chinese researchers have probed the science underlying the ideal drinking temperature for alcoholic beverages and found that beer or white wine should be drunk chilled, and red wine at room temperature. But some whiskeys or sake are best warmed.

The researchers at the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, have found that the temperature of the alcoholic beverage influences the way ethanol-water mixture concentrations cluster in the liquid, altering the taste of ethanol.

“Our findings prove that… the proper drinking temperatures for different alcoholic beverages are not only based on experience but correspond to… different states of molecular clusters of ethanol-water mixtures,” Lei Jiang, a professor of physical chemistry at the institute, and his colleagues said in their study.

The study, published in the journal Matter on Wednesday, has shown that the ethanol-like taste of alcoholic beverages gets enhanced or lowered at different temperatures, depending on whether the ethanol and water form chain-like clusters or pyramid-like clusters at the molecular level.

At low ethanol concentrations, the ethanol forms more pyramid-like structures around water molecules, while at higher ethanol concentrations, the ethanol forms more chain-like clusters.

The study showed that in five per cent — or beer-like — ethanol solutions, chain-like clusters are enhanced at 5°C.

Amid such changes, at low temperatures, the taste of alcohol is enhanced even at low ethanol concentrations. “This is why we drink cold beer,” Jiang, who led the study, said in a media release from the journal.

Jiang and his colleagues used a technique called nuclear magnetic resonance spectroscopy and molecular dynamics to observe how the ethanol-water mixtures behave at different concentrations of ethanol and different temperatures. They also conducted tasting experiments to document the impact.

The researchers found that even non-professional tasters could clearly tell the difference between low-alcohol and high-alcohol beers after cooling, which was, however, confusing for them at room temperature.

Professional tasters provided a more accurate description of an enhanced sensation and ethanol-like tastes of both low-alcohol and high-alcohol beers
after cooling.

The study found that 39 per cent and 52 per cent ethanol solutions — like the ethanol concentrations in baijiu, a type of Chinese whiskey — have distinct clusters at room temperature but this difference disappears at the higher temperature of 40°C. At the higher temperature, both the ethanol concentrations have an enhanced ethanol-like taste.

The enhanced ethanol-like taste might explain the habit of drinking warm baijiu or sake because, at higher temperatures, even lower-volume alcoholic beverages taste similar to higher-volume alcoholic beverages.