Studies on the Clarification of Real Ale - Part One

By J.D. Kervin, J.M. Moore, B.M. Pepin & D.A. Peters

Abstract
The rates of sedimentation of solids in a local microbrewed ale were evaluated by observing the change in height of the turbid region in a sample, as well as monitoring the light transmittance through the clear (upper) portion and the turbid (lower) portion. Similar data were collected when Polyclar SB-1OO, Polyclar-1O, Isinglass, Clearfine, and Papain were used to promote the rate of settling. It was found that all five settling aids caused the ale to clear faster than the unaided ale. Additionally, the settling aids produced somewhat clearer ale (in shorter times), and the sediment formed in tighter cakes at the bottom of the vessel when using the settling aid. A taste test conducted with a panel of seven individuals generally picked the ale treated with Isinglass as the least favorite product, but it was not certain that oxygen contamination levels had not affected that sample. The majority indicated that it was difficult to distinguish between the three samples used in the test.
 

Sintesis
Las velocidades de sedimentaci6n de los s61idos de una cerveza hecha en una micro-cerveceria local fueron evaluadas observando el cambio en altura de la region turbia de una muestra y monitorizando la transmision de luz a traves de la porcion transparente (superior) y la porcion turbia (inferior). Se recolectaron datos similares cuando fueron usados Polyclar SB-IOO, Polyclar-IO , Isinglass, Clearfine y Papailla para favorecer la velocidad de asentamiento. Se encontro que todas las cinco substancias de ayuda para a entamiento causaron un aclaramiento mas rapido de la cerveza con respecto a otra cerveza sin dichas substancias. Ademas, las ayuda para asent.amiento produjeron una cerveza un poco mas clara (en per rod os de ticmpo mas reducidos) y el sedimento se formo en conglomerados mas compactos en el fondo del recipiente cuando se usaron dichas ayudas. En una prueba degustacion lIevada a cabo por un panel de siete personas, se observo, en general, que dichas personas escogieron la cerveza tratada con Isinglass como el producto menos favorito; no se supo con certeza si los niveles de contaminacion de oxigeno habian o no afectado dicha muestra. La mayoria indico que era dificil distinguir las tres muestras usadas en la prueba.