Why does beer foam? Let’s find out!

Why Does Beer Foam?

Have you ever wondered why does beer foam, and why is it foaming excessively when poured from a beverage dispenser? Let’s delve into the science behind beer foam, and why excessive foam might be coming from your bar or restaurant’s beverage equipment.

Understanding Beer Foam Formation

Beer foam, or the head, is an integral part of the beer-drinking experience. It not only enhances the visual appeal but also contributes to the aroma, taste, and overall mouthfeel. Why does beer foam? Well, the formation of foam in beer is primarily due to the presence of proteins, carbon dioxide (CO2), and other compounds.

Proteins: Beer contains proteins derived from malted barley. These proteins, particularly a group known as hydrophobic proteins, are responsible for creating a stable foam. They form a complex network at the air-liquid interface, trapping gas bubbles and stabilizing the foam structure.

Carbon Dioxide (CO2): During fermentation, yeast converts sugars into alcohol and CO2. When beer is carbonated, additional CO2 is dissolved under pressure. When the beer is poured into a glass, the release of pressure causes the dissolved CO2 to escape as gas bubbles, contributing to foam formation.

Other Compounds: Various compounds found in beer, such as hop oils, polyphenols, and fatty acids, interact with proteins and CO2 to further stabilize the foam. These compounds can also contribute to foam retention and influence the characteristics of the foam, such as its texture and thickness.

Why Does Beer Foam? Factors Influence Foam Stability

While beer foam is generally desired, excessive foaming from beverage dispensers can be problematic. Chances are, if you’re wondering why does beer foam, this might be the case with your equipment. Draft beer systems can introduce additional factors that influence foam formation, including:

  • Temperature and Pressure: Beer dispensers typically use a combination of temperature and pressure to maintain the beer’s freshness and carbonation. If the temperature or pressure settings are not properly calibrated, it can lead to over-carbonation, causing excessive foam during pouring. Pouring most draft beer styles at a temperature of 38°F and ensuring the flow rate for each pint is
    2-oz-per-second will prevent these issues.
  • Line Cleanliness: Beverage dispensers have complex systems of lines and taps that transport the beer. If these lines are not adequately cleaned or maintained, they can accumulate residue, yeast, or bacteria. Such contamination can disrupt the delicate balance of proteins and CO2, leading to excessive foaming. Bar and restaurant owners should ensure the beverage dispensing system is cleaned every two weeks (and be sure your glassware is beer clean too)!
  • Improper Pouring Technique: The manner in which beer is poured from a dispenser can also contribute to excessive foam. Pouring too quickly or at an incorrect angle can create turbulence and disrupt the foam formation process. Employees should open the beer faucet completely when pouring draft beer and pour at a 45-degree angle.

Contact Stuever & Sons If You’re Dispensing Too Much Foam

If you find that your beverage dispensing equipment is consistently pouring an excessive amount of foam, even after following the recommendations above, there’s no need to worry. You can rely on the expertise of our dedicated team at Stuever & Sons to address the issue.

Our professionals specialize in repairing draft beer systems, ensuring that your equipment functions flawlessly. Additionally, we offer regular beer line cleanings to maintain the optimal quality of your brews. Whether it’s troubleshooting foam-related problems or conducting routine maintenance, our team is well-equipped to provide effective solutions. Don’t hesitate to reach out to us for all your beer tap system needs.

Scroll to Top