The Secret to the Perfect Pint Unveiled: Foam Lovers Rejoice, Others Beware

Being handed a pint with a head is a common source of anger among pub-goers.

But a new study suggests that the more foam there is in a beer, the more aroma the drink has.

In laboratory tests, scientists in Japan found that a prominent layer of foam makes beer up to twice as aromatic, serving as a “tempting plate” of the beer’s overall flavor.

The aromatic compounds are concentrated in millions of individual bubbles in the whipped foam layer of the beer.

When each of them collapses, aromatic components along with carbon dioxide are released into the atmosphere, which increases the perception of flavor.

The study was led by researchers from Kyushu Sangyo University in Fukuoka and Asahi, the Japanese brewing company.

“Beer foam plays a novel role as an aroma carrier, specifically promoting the release of some characteristic aroma compounds,” they state.

“Beer foam can promote the release of specific and attractive aromas to encourage beer consumption,” they state in their article.

«The foam acts as an efficient gas exchange surface that directs the aroma towards the drinker’s olfactory sensors.

“It provides the drinker with the tempting first course in terms of the quality of the flavours, the freshness, the freshness and the wholesomeness of the beer.”

Whether fruity, malty or earthy, we can perceive the nuanced flavors of beer thanks to the olfactory receptors in our nose.

Meanwhile, the taste buds on our tongue detect the “flavor” of the beer, whether sweet, sour or bitter.

There are typically hundreds of aromatic compounds in a beer, which are released during fermentation during the brewing process.

Examples include isoamyl acetate, a compound that smells like banana or pear, and ethyl decanoate, which is described as having lactic and fruity aromas.

For the study, the team used Japanese beer “purchased at the local Japanese market.”

Although three of the study authors were from Asahi, the brand of beer or whether they used ale or lager was not revealed.

The beer was placed in a sealed glass cylinder so that the aromas could only escape through a glass straw at the top, assisted by an inward flow of nitrogen.

The aromas were monitored with a special type of mass spectrometer, an instrument that measures compounds in real time in an air sample.

Scientists captured the aromas of the beer before and foamed it using ultrasonic waves.

This ultrasonic treatment mimicked the physical process a beer might undergo when poured into a glass in a pub.

This allowed them to monitor the aromatic compounds that would be inhaled through the nose of a drinker of both a foamy beer and a still beer.

Overall, the team found that “concentrated rates of aromatic components” were 1.3 to 1.9 times higher in foamed beer, compared to non-foamed beer.

They also found evidence that the more “hydrophobic” or water-repellent a flavor is, the more likely it is to concentrate in the foam.

But they admit that the absence of foam accentuates hydrophilic flavors in the actual liquid, such as malt and caramel.

‘[We] has clarified the novel role of beer foam as an aroma carrier,” they state in their article, published in Journal of the American Society of Brewing Chemists.

“Beer foam can promote the release of specific and attractive aromas to encourage beer consumption.”

Researchers list other benefits of beer foam, including acting as a “lid” to prevent the escape of carbon dioxide gas, keeping the drink fizzy.

“The creamy foam provides a unique mouthfeel on the upper lip when we drink it, so it is believed to contribute to making the beer delicious,” they add.

They also say that the contrast between the foam and the color of the liquid “is a symbol of the beauty of the beer.”