Beer foam prevents it from spilling over

Beer foam prevents it from spilling over

We are searching data for your request:

Forums and discussions:
Manuals and reference books:
Data from registers:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.

Foam of the beer flower counteracts the spillover

The foam of the beer prevents the drink from spilling over to a certain extent, while liquids without a foam layer run more easily over the edges. An American-French research team led by Alban Sauret from the French research center CNRS Saint-Gobain has now investigated the effect of the foam on the movement of the liquid within a container and found that a thin layer of foam already significantly dampens the dynamics of the liquid.

When a container is set in motion, the free surface of the liquid begins to vibrate inside and, if in doubt, spill over. "However, beer doesn't spill over water as easily, which means that foam can be used to prevent it from spilling over," says Alban Sauret and colleagues in the physics of fluids magazine. Sauret reports that the thought of the examinations came to him while drinking a frothy Guinness that hardly spilled even with strong movements of the glass.

Effects of the foam overlay on fluid movement Together with Emilie Dressaire from New York University and other colleagues from Princeton University in New Jersey, Alban Sauret has analyzed the phenomenon of motion damping through foam in the current study. Specially made, rectangular containers were filled with a surfactant solution and air was pumped through the liquid from below with a fine needle. A foam was formed from bubbles of uniform size. Now the researchers began to set the container in motion and filmed the behavior of the liquid or foam using a high-speed camera. They recognized that just a few layers of foam bubbles were sufficient to significantly dampen the dynamics of the liquid in the containers or their vibration.

Even a thin layer of foam is sufficient to dampen movement According to the scientists, the friction of the foam bubbles on the vessel wall is decisive for the energy-absorbing effect of the foam. Foam bubbles without contact with the wall would hardly have any influence on the movement of the liquid. Furthermore, Sauret and colleagues explain that five layers of foam bubbles are sufficient to achieve a comprehensive damping of the movement. Since the upper layer of the foam bubbles is hardly moving, additional foam cannot bring about a significant additional reduction in movement.

Numerous industrial applications possible? Although most people are more aware of the dampening effect of the foam on the movement of the liquid from beer, latte macchiato or cappuccino, the researchers believe that the foam could develop its usefulness elsewhere. You are thinking, for example, of the transport of oil and LPG in tankers. Because here the sloshing dynamics can exert considerable pressure on the walls of a container and, in the worst case, lead to its destruction. Numerous industrial applications are possible for the foam, according to Sauret and colleagues. Last but not least, the foam can also be used to safely transport rocket fuel - thanks to the sight of a perfect beer flower. (fp)


Image: Tim Reckmann /

Author and source information

Video: Under the Influence of Beer Foam