• Spain's news in English

Scientists unlock mystery of foaming beer

George Mills · 21 Jan 2014, 14:03

Published: 21 Jan 2014 14:03 GMT+01:00

Facebook Twitter Google+ reddit

It all started in a bar: that's how scientists from Madrid's Charles III University (UC3M) have described the beginnings of their year-long study.

The clashing of base of one beer bottle against the neck of a second bottle got researchers talking about why the beer frothed up.

When no one could provide a convincing reason, the team took their research back to the laboratory.

Using lasers, high-speed photography and bottles of the Spanish beer Mahou, the team — together with scientists at France's Jean le Rond D’Alembert Institute — discovered that knocking two bottles together caused a mini-explosion of carbon dioxide.

Usually carbon dioxide is released very slowly but when bottles collide, this happens in a fraction of a second.

This process involves three separate phases. First, the sudden vertical impact on the mouth of a beer bottle causes a compression wave that spreads through the glass towards the bottom. 

When this wave reaches the bottom of the bottle, it rebounds as an expansion wave that travels to free surface, where it bounces back again.

Next this chain reaction leads to the collapse of air pockets, or bubbles, in the beer, and this creates a cloud of tiny 'daughter' bubbles that expand much faster than their 'mothers' due to their smaller size. 

Lastly, those bubbles expand rapidly and race towards the top of the bottle because they are lighter than the beer that surrounds them. This explosive forces results in the froth.

"These clouds of foam look like the mushroom cloud of a nuclear explosion," Javier Rodríguez, a professor of UCSM's Department of Thermal Engineering and Fluids told Spanish science news agency SINC.

But the research isn't just a novelty.

Story continues below…

"One of the applications of this project is the prediction of the quantity of gas which is produced after the eruption of a volcano," explained Daniel Fuster from the Jean le Rond D’Alembert Institute.

The study could also help improve the design of ship propellers and anti-shock structures for buildings.

"This is one of the big advantages of basic research. You learn about physics on the cheap with systems as simple as a bottle of beer and later this helps you understand and try and solve large problems," said Rodríguez of the study.

George Mills (george.mills@thelocal.com)

Facebook Twitter Google+ reddit

Your comments about this article

Today's headlines
Bulls replace guard dogs at scrap yard in Valencia
Two bulls will be patrolling the scrap yard in eastern Spain. Archive photo: AFP

Guard dogs were not proving enough of a deterrent to thieves at a car breakers yard in eastern Spain so the owner has brought in a pair of fighting bulls.

Two-headed shark born in Spanish laboratory
Scientists are studying the rare find. Photo: IBIMA / University of Malaga

Scientists at the University of Malaga found the embryo of a shark with two heads and just one body.

Spain under pressure to stop refuel of Russian warships
Russian aircraft carrier Admiral Kuznetsov is due to arrive in Ceuta. Photo: Mil Ru / Wikimedia

Spain is facing international pressure to refuse permission for a Russian warship flotilla to refuel in Ceuta en route to continuing airstrikes against the Syrian city of Aleppo.

Most wanted: Fugitive rapist arrested in Tenerife
Mohammed Jahangir Alam was arrested n Tenerife. Photo: Crimestoppers.

Mohammed Jahangir Alam, one of Britain's most wanted fugitives, who fled the country in 2008 after allegedly raping a woman, was found working in Tenerife.

Spain's Rajoy says king has tasked him with forming govt
Photo: AFP

Spain's king on Tuesday tasked Mariano Rajoy with forming a government, taking the acting conservative prime minister a step closer to power again after a 10-month political deadlock.

Two imams arrested in Ibiza resort over 'Isis support'
The men were arrested in the resort of Sant Antoni de Portmany. Photo: Jose A / Flickr

Two Moroccan imams at a mosque on the Spanish resort island of Ibiza were arrested Tuesday on suspicion of backing the Islamic State group and inciting jihad.

Balearic Islands choose to keep summertime forever
The islands will have longer evenings during winter. Photo: AFP

The Balearic Islands want to keep summertime when the rest of Spain turns the clocks back on Sunday.

  Brazilian had 'uncontrollable desire to kill': Spain police
Francois Patrick Nogueira Gouveia has been charged with murdering his uncle, his wife and their two children. Photo: Guardia Civil.

A Brazilian teenager accused of dismembering his uncle and aunt and killing their two young sons in a grisly crime that shocked Spain had an "uncontrollable desire to kill", police said on Monday.

Man rescued from bin after climbing in to find old clothes
Photo: Policía Local Murcia

Police were called after passersby reported hearing a man calling for help from within a rubbish bin in the Vistabella neighbourhood of Murcia, southern Spain.

Spain faces crucial week as conservatives re-take power
Mariano Rajoy hopes to form a government this week. Photo: AFP

Spain entered a crucial week as acting conservative PM Mariano Rajoy prepared to re-take power, ending ten rollercoaster months without government marked by hope and disillusion.

Analysis & Opinion
Out of the dark: Five years on from Eta ceasefire
Sponsored Article
Last chance to vote absentee in the US elections
Spanish 'La Mafia' restaurants banned after Italian complaint
Spain's top court overturns bullfighting ban in Catalonia
Hunt launched for ten most wanted Brit fugitives hiding out in Spain
Napflix: Spaniards launch very boring TV channel for siestas
Madrid parish church faces fine over 'too noisy' bells
Celebrate expat life at Madrid’s THRIVE convention
Fury after kids told to bring their own loo roll to school
Disney announces plans for Don Quixote action movie
Activist tells 8-yr-old matador wannabe with cancer 'just die'
King to make last minute push to avoid third vote in Spain
Amazing photos of Catalonia's 'human tower' contest
What's on in Spain: October 2016
'No way, Jose! You'll never get your hands on our Rock'
Recipe: How to make a classic Spanish tortilla de patatas
Chorizo in paella? Go back to cooking school Jamie Oliver
Spain in eye of a perfect storm after 10 months without govt
Thousands share clips of life for 'Spain in a Day' film
Ten incredible Spain locations for Game of Thrones season 7
Analysis & Opinion
Why moving to Spain could be the best decision of your life
Seven reasons why autumn is the very best season in Spain
Spanish study finds four types of personality. Which are you?
New search underway for civil war grave of poet Lorca
jobs available