Some Factors Impacting Beer Foam
Peer-Reviewed Paper
MBAA TQ vol. 45, no. 4, 2008, pp.
332-336 |
VIEW ARTICLE
Charles Bamforth, Alexandros Kalathas, Yann Maurin, and Candace Wallin. Department of Food Science & Technology, University of California, Davis, CA.
Abstract
The Steinfurth foam stability tester was studied and shown to be a robust
device for assessing the foam stability of beer. It was used to show that beers
differ in their susceptibility to lipids as foam-destabilizing agents. Although
all the beers tested showed some recovery from foam inhibition when the contact
time between the lipid and beer was increased, in no instance was full recovery
observed. Similarly, beers differed in their susceptibility to detergent used
for washing glasses. Over the range of beer dispense temperatures normally used,
there was no measureable impact on foam stability. Beers differed in the impact
that pH had on their foams. For a North American pale ale, there was an increase
in foam stability as pH was lowered over the range of 5 to 3.3, whereas a North
American lager showed maximum foam stability in the range of 4 to 4.5, with foam
stability decreasing on either side of that range.
Keywords: beer, detergent, foam, lipids, pH, Steinfurth foam stability tester
S�ntesis
Se estudi� el aparato Steinfurth para determinar la estabilidad de la espuma;
se pudo comprobar que este era un dispositivo robusto para evaluar la
estabilidad de la espuma de cerveza. Se pudo demostrar que las cervezas tienen
diferentes susceptibilidades a los l�pidos como agentes desestabilizadores de la
espuma. Si bien todas las cervezas testadas mostraron una recuperaci�n parcial
a la inhibici�n de espuma al aumentar el tiempo de contacto de los l�pidos con
la cerveza, en ning�n caso hubo una recuperaci�n total. Las cervezas tambi�n
difer�an en su susceptibilidad a los detergentes usados en la limpieza de vasos.
No se detect� ninguna influencia de la temperatura (en el rango normal de uso)
al servir la cerveza sobre la estabilidad de la espuma. Las cervezas
reaccionaron de manera disimilar en cuanto al efecto del pH sobre la espuma. La
estabilidad de la espuma de un �pale ale� norteamericano aument� al bajar la
espuma de 5 a 3.3, mientras que un �lager� norteamericano tuvo su m�xima
estabilidad en el rango de 4 a 4.5, bajando la estabilidad en ambos lados de
este rango.
Palabras claves: aparato Steinfurth para estabilidad de espuma, cerveza,
detergente, espuma, l�pidos, pH
