Drink to this: New study paves way towards the ‘perfect’ head of beer

MANCHESTER, England — It’s a quest that bar-goers and beer enthusiasts have been on for generations: finding that elusive perfect head, or foamy top, of beer. Most have already given up on finding a head of beer that remains until the drink is gone, considering it about as realistic as the Loch Ness monster or Bigfoot, but now a new study is potentially paving the way towards making this beer fantasy a reality.

So what’s the key to this breakthrough? According to head researcher Dr. Richard Campbell of the University of Manchester, it’s the subatomic particles known as neutrons. But besides just beer, Campbell says that his work can also drastically improve the quality of other foam-related products such as creamy coffee toppings, shampoos, firefighting foams, and oil absorbent foams used in the event of environmental disasters.

The research was performed primarily at the Institut Laue-Langevin in France, home to one of the planet’s most intense neutron sources. Within this facility, Dr. Campbell fired neutron beams at the substances typically used to produce foam.

“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. The difference is that the information is on a molecular level that we cannot see with our eyes,” Dr. Campbell explains in a release.

The research team used this approach to analyze foam mixtures containing surfactant, a compound known to lower surface tension, and a polymer used in shampoos, to better understand these substances and how they can be used to create the perfect form of foam.

According to the study’s authors, this line of research may be able to produce a pint of beer that allows drinkers to enjoy its foamy head all the way to the bottom of the glass. This new application of neuron technology may also be able to produce more efficient cleaning detergents, more effective fire extinguishing foams, and better oil cleaning products for the world’s oceans.

“For decades scientists have tried to get a handle on how to control reliably the lifetime and stability of foams made from liquids that contain mixed additives. While the behavior of foams made up with just one additive is quite well understood. As soon as mixtures like those used in products were studied the results from research studies failed to paint a consistent picture,” Dr. Campbell comments. “This is important, as some products benefit from foams that are ultra-stable and others from foams that are very unstable.”

To get to the heart of the problem, the research team studied the “building blocks” of the foam bubbles, referred to as foam films. By reflecting neutrons off of these liquid samples, they were able to formulate a new way of arranging the additives that should promote a sense of stability that stops the bubbles from bursting.

“Foams are used in many products – and product developers have long tried to improve them so they are better equipped for the task they are designed to tackle, but researchers have simply been on a different track, thinking of general surface properties and not about the structures created when different molecules assemble at the surface of bubbles,” Dr. Campbell says. “It was only through our use of neutrons at a world-leading facility that it was possible to make this advance because only this measurement technique could tell us how the different additives arrange themselves at the liquid surface to provide foam film stability.

“There are a number of installations in the UK and across Europe which produce neutrons – and these research facilities are essential in carrying out this sort of work,” he concludes. “We think this work represents a clear first indication that our new approach could be applied to a range of systems to aid the development of products that can make an impact in materials science and on the environment.”

The study is published in the scientific journal Chemical Communications.