Triple-fermented beers produce the most stable foam, while single-fermented beers, including lagers, produce froth that collapses quickly. Beer foam consists of many small air bubbles separated by thin liquid films. Gravity and surrounding-bubble pressure thin the films, causing bubbles to pop and the foam to collapse. Foam stability varies with the form of a barley-derived protein called Liquid Transfer Protein 1 (LTP1). In single-fermentation beers LTP1 adopts a globular form and arranges densely as small spherical particles on bubble surfaces, producing fragile foams. Advanced imaging of thin films and protein aggregates reveals the mechanisms and enables breweries to improve foam stability.
A flat pint of beer with no head is a common gripe among pub-goers. And while the bar staff's pint-pulling technique is often assumed to be the cause, scientists have discovered that the stability of beer foam is also highly dependent on the chemical makeup of the brew. Triple fermented beers have the most stable foams, the study found, while the froth created by single fermentation beers, including lagers, are inherently more likely to collapse before you have time to take the first sip.
Like any other foam, beer foam is made of many small bubbles of air, separated from each other by thin films of liquid. Under the pull of gravity and the pressure exerted by surrounding bubbles, the films of liquid slowly thin out, the bubbles pop and the foam collapses. But the rate at which this process occurs was found to vary depending on the form of a barley-derived protein, called Liquid Transfer Protein 1 (LTP1).
Collection
[
|
...
]