Method and device for determining a foam density of foam in beverage containers utilizing the Tyndall effect, and having a focused light bundle emitted into the foam by means of a light source, where the light bundle is refracted in the foam and a scattered ray becomes visible on a surface of the foam. Via a measurement of the contour of such a light spot, conclusions on the foam density can be drawn. For this, one or several lasers can be integrated into existing filling level measuring means which are coupled to the already existing measuring means.