This study is beer-reviewed.
While a frothy beer might be a nuisance to bar patrons who hope to hop a train to tipsy town and guzzle down the drink, the foamy topper actually packs a lot of flavor, according to a new study.
The paper, published in the Journal of the American Society of Brewing Chemists, found that a beer’s foam makes it doubly aromatic, thereby making it more delicious.
This bubble-bursting study was conducted by researchers from Kyushu Sangyo University in Fukuoka, Japan as well as by the Japanese brewing company Asahi.
The study authors explained that the bubbles in the beer hold flavor compounds and when a bubble bursts, the flavor is released into the air — right into the drinker’s nose.
“The foam acts as an efficient gas exchange surface funneling aromas toward the drinker’s olfactory sensors, and it provides a drinker’s first tantalizing entrée as to the quality of the beer’s flavor, freshness, refreshingness, and wholesomeness,” read the study’s introduction.
The foam also acts as a “lid” for carbon dioxide, which escapes and takes the flavor with it.
“The foam prevents beer from losing its flavor due to changes in its composition caused by exposure to air,” the study authors said.
The authors used two beers purchased from a local Japanese market, though they did not disclose the brands.
They measured the aroma in the beer before it was frothed and after by using ultrasonic waves that mimic the way beer behaves when it’s poured into a glass. This allowed them to measure the scent of a flat beer and a frothed beer.
The researchers found that the aroma components were 1.3 to 1.9 times higher in the beer with a frothier head compared to the flat beer.
They found a beer that is more hydrophobic, meaning it repels water, is more likely to have flavor captured in the foam. Barley, hops and wheat, key components of beer, have proteins that are very hydrophobic, according to American Craft Beer.
Having less foam could have some taste benefits, however, such as highlighting the flavor of malt and caramel.
In addition to being a “carrier of aroma,” the study says the foamy top of a beer provides a multisensory drinking experience.
“Creamy foam provides a unique mouthfeel on the upper lip when we drink it, and so it is thought to play a role in making beer delicious,” they wrote.
They also say the color palette of the foam compared to a beer’s liquid “is a symbol of beer’s beauty.”
Scientists don’t only tout the flavor of beer. A study from 2017 found that beer makes people happy.
A study last year found that in moderation, beer might help prevent people from getting Alzheimer’s.