What is commonly used to cool a beer glass before serving?

Chilling a beer glass before serving is often done to enhance the drinking experience by maintaining the beer's temperature for a longer period. When considering the method that is commonly used, spraying with water stands out as an effective technique in many bar settings.

When a glass is sprayed with water, the water quickly evaporates, creating a cooling effect due to the energy required for the phase change from liquid to vapor. This method is efficient and allows bartenders to rapidly prepare glasses without the risk of melting ice, which could dilute the beer if it contacts the liquid directly.

The other methods have limitations. For example, ice cubes can chill a glass, but they also pose the risk of melting, which could affect the beer served in it. Warm water is ineffective for chilling as it would, instead, raise the temperature of the glass. Chilled metal can be used but is not as common in casual settings, as it may require specialized equipment like frosted mugs or pre-chilled glassware. Therefore, spraying with water is often preferred for its practical cooling effects in a fast-paced bar environment.