28th May, 2014 by Lauren Eads
Researchers at Cornell University have reached their verdict on what makes a perfect pint, revealing a complex combination of chemicals needed to achieve the best foamy head.
Cornell’s Karl Siebert. Credit: Jason Koski/Cornel University
Students on the University’s College of Agriculture and Life Sciences course; The Science and Technology of Beer, led by Professor Karl Siebert, studied what chemicals combined to make the perfect foam, taking a pint of non-alcoholic beer, commercial beer and lager.
Siebert, professor of food science and technology at the New York State Agricultural Experiment Station in Geneva, and professor at Cornel University, said: “To some beer aficionados, the sign of a good head – the proper consistency, color, height, duration – is to draw a face with your finger in the foam, before taking the first sip.
“If the face is still there, when the glass is drained and the liquid is gone – that’s seriously good foam.”
Ultimately, the study found that the key to a perfect head lies with the amount of ethanol that is combined with its key ingredient, barley lipid transfer protein (LTP1).
The perfect balance was found when medium levels of ethanol were mixed with (LTP1) at lower pH levels, which researchers said improved the amount and quality of a drink’s head, while salt was found to reduce the amount of foam.
“Dissolved gases in the beer – carbon dioxide and, in some instances, nitrogen – play a role. So do acidity, some ions, ethanol levels, viscosity and numerous other factors that have been tried by brewers and scientifically tested; but LTP1 is the key to perfect beer foam.”
The results will be published in the next issue of the Journal of the American Society of Brewing Chemists.