VIEW ARTICLE    DOI: 10.1094/ASBCJ-35-0197

Gales Foam Analyzer-A Novel Approach to Beer Foam Measurement. Peter W. Gales, Jos. Schlitz Brewing Co., Milwaukee, WI 53201. J. Am. Soc. Brew. Chem. 35:0197, 1977.

A new method for the measurement of beer foam is described. The method uses an optoelectronic device to measure the liquid runoff rate. The device, called the Gales Foam Analyzer, consists of a glass cylinder in which foam is generated, a series of phototransistors placed in opposition to a series of light-emitting diodes and a counting circuit. In operation, foam is generated in the glass cylinder. A series of 15 light-emitting diodes is cyclically pulsed to produce radiant energy at various levels of the foam cylinder. The presence of foam at a given level blocks the light path so that no signal is received by the phototransistor at that level. As the liquid level rises, a given level will then contain beer, which allows radiation to reach the phototransistor, activating the counting circuit. In an analytical determination, the contents of the foam cylinder are repetitively scanned for a predetermined time period. The foam analyzer circuitry totalizes the count, thereby giving a measure of the liquid runoff. When applied to a series of American lagers, reproducibility is good and differences between beers are shown.

Keywords: Analytical method, Beer foam, Gales Foam Analyzer.