It might not be one of the most pressing problems the world faces these days, but who doesn’t want to pour the perfect pint? It’s a challenge we face daily and sometimes a foamy head can be elusive. Some beers may have one, while others may not. And once it’s poured, that glorious head all but disappears shortly thereafter.
But scientists in the U.K., Germany, and in France may have produced a foamy head that lasts through the entire tasting — long enough before you need that next refill.
In pursuit of that perfect pint, the scientists have been exploring how physics could be used to give beer drinkers an improved version of their favorite grain-based alcoholic beverage.
And this is where subatomic particles come in. Scientist Richard Campbell of the University of Manchester is so obsessed with the stuff that he led a research team through some futuristic experiments, which have involved shooting neutrons into different liquids used to make foams, which could mean a breakthrough for more than just beer.
Since a good head helps release the aromas in beer, along with providing a pleasant mouthfeel, that’s an innovation likely to find far greater public approval than killer robots or ever more omnipresent surveillance tech.
By firing beams of neutrons at liquids used to make foams, the scientists involved in the research uncovered new information about the way that additives affect the structure of foam-causing bubbles in liquid. These insights could be used to create foam with more stability that does not burst.
“Just like when we see light reflecting off a shiny object and our brains help us identify it from its appearance, when neutrons reflect up off a liquid they are fired at we can use a computer to reveal crucial information about its surface,” lead researcher Dr. Richard Campbell from The University of Manchester said in a statement. “The difference is that the information is on a molecular level that we cannot see with our eyes.”
The neutron firing was carried out at the Institut Laue-Langevin in France. This institute has one of the world’s “most intense” neutron reactors for use by the international scientific community. “It was only through our use of neutrons at a world-leading facility that it was possible to make this advance,” Campbell continued. “Because only this measurement technique could tell us how the different additives arrange themselves at the liquid surface to provide foam film stability.”
Previous research had not really zeroed in on how molecules arrange themselves on the surface of bubbles. To figure out how to create the best foam ever, the researchers zoomed in liquids containing surfactants, which are chemicals that dial down surface tension. The ideal stability of foam depends on the application. Obviously, beer demands a thick, creamy foam that won’t collapse, but the last thing you’d want if you owned a laundromat would be mountains and mountains of it overflowing everywhere.
Beyond brews, foam can go from the froth on your cappuccino to the lather in your shampoo to lifesaving foams used for firefighting and absorbing the potentially lethal aftermath of oil spills. Remember those commercials that showed animals caught in oil spills rescued and rinsed off with dish soap? Oil absorption is another property of foam that was investigated in this study. Campbell used the high-tech equipment at the Institut Laue-Langevin in France to blast foaming liquids with neutrons, which reflect off the liquid they are shot into and (when analyzed by a computer) reveal what is going on at a molecular level. Liquids that use multiple additives are what the research was focused on. Beer qualifies.
While you might have to wait a few years past closing time to get the foamy top of your dreams, there probably will be a day when that foam looks just like it did the moment you poured yourself a cold one.
A paper describing the work was recently published in the journal Chemical Communications.