A New Analytical Technique for Brewinq Analyses - Application of Acoustic Impedance Attenuation and Velocity Measurements at Ultrasonic Frequencies to Brewing Analyses

By Ian S. Forrest and D. Skrgatic Canongate Technology Ltd., Edinburgh, Scotland 1999 EBC Poster

Abstract
Sound velocity has been widely accepted in brewing for measurement of original gravity and alcohol, but can only be used in clear liq- uids with little suspended material and no bubbles. We have developed a robust, hygienic and cost effective instrument, which extends the measurement to include acoustic impedance and attenuation. This produces a versatile instrument, which can measure the concentration of solute in the presence of solids or bubbles, and of dispersed material in suspension. Examples include the measurement of malt saccharification, fermentation gravity, cell density in concentrated yeast slurries and the detection of powder breakthrough from filters.
Keywords: Acoustic Velocity, Acoustic Impedance, Perlite-Acoustic Properties, Acoustic Attenuation  

Sintesis
La velocidad del; sonido ha sido bastante aceptada en la elabo- ration de la cerveza para la medida de la gravedad original y el alcohol, pero solo puede ser usada en ll'quidos claros con poco material suspendido y son burbujas. Nosotros hemos desarrollado un instrumento resistente, higienico y economico que extiende ta medida hasta incluir la impedancia y atenuacion acusticas. Esto produce un instrumento versatil, que puede medir la concentracirjn del soluto en la presencia de solidos o burbujas y del material disperso en suspension. Algunos ejemplos incluyen la medida de la sacarinificacion de la malta, la gravedad de la ferrnentacion, la densidad de la cclula cn las lechadas de levadura concentradas y la deteccion del polvo despendido de los filtros.