Table of Contents

Return to previous page

View Article

Influence of hop bitter acids and their derivatives on beer foam stability evaluated using customer-oriented Foam Collapse Time (FCT) method
K. Takoi

We successfully developed new automated ‘FCT (Foam Collapse Time)’ system for the evaluation of visual foam stability in order to get a useful knowledge for improving practical foam stability. The FCT value is defined as the required time for a reduction of the 40 % of glass hight (32 mm) of foam layer to a single layer in a prescribed glass. The improved FCT pouring apparatus was coupled with automated turntable for 6 glasses, electronic balance, and CCD-cameras (side and upper) for measuring the foam layer (mm) and the collapse point. Based on automatically collected data, the FCT value could be statistically calculated by specialized software on the control PC. Using this system, we confirmed an importance of hop bitter acids and their derivatives, which could affect the strength of foam membrane, for visual foam stability evaluating by FCT. From comparison between FCT, Sigma, and NIBEM methods, it was suggested that detectability for foam membrane strength was more sensitive in FCT and NIBEM than Sigma, and that foam membrane strength could also affect foam lacing.

Descriptors: beers, hops, bitter acids, isohumulone, Rho-isohumulone, tetrahydro-isohumulone, foam stability

BrewingScience, 74 (November/December 2021), pp. 141-150