Effects of Spent Grains or their Extract on Yeast Performance

Hisao Kado, S. Ishii, K. Takoi, Y. Mitani and K. Shinotsuka. Poster presented at the MBAA 111th Anniversary Convention, Minneapolis, Minnesota, September, 1998.

Abstract
It is known that the ingredient of barley husk enhances yeast performance in fermentation. We found that the spent grains also showed the same effect when added in wort to shorten fermentation time by one or two days. But the addition of spent grains reduced the quality of the beer, due to fatty acid flavor and astringent taste based on the substances derived from the spent grains. We purified spent grains to obtain effective fractions against yeast performance and to remove unnecessary substances such as fats and other materials which have negative influences in beer. Then, by extracting from spent grains with acid, we obtained an effective fraction. It showed the same effect when added 1/100 dose of untreated spent grains, and the beer quality produced did not have the defect characters of the beer which was fermented with untreated spent grain.
Keywords: spent grains, yeast, zinc  

Sintesis
Es conocido que el ingrediente de la cascara de cebada. mejora el rendirmento de la levadura en la fermentacion. Hernos encontrado que el afrecho tarnbien demonstro el miso efecto cuando es ahadido al mosto reduciendo el tiernpo de fermentacion de uno a dos dias. Pero la adicion de afrecho reduJo la calidad de la cerveza, debido al sabor de los acidos grasos y sabor astringente, basado en las sustancias derivadas del afrecho. Nosotros purificarnos al afrecho para obtener fracciones efectivas contra rendimiento de la levadura y para remover sustancias no necesarias conto grasas y otros materiales que tienen efecto negativo en la cerveza. Luego, al extraer del afrecho, con acido, obtuvimos una fraccion efectiva. Demonstro ell mismo efecto cuando, adicionamos 1/100 de la dosis de afrecho no tratado, y la calidad de la cerveza producida no tuvieron las caracteristicas de defecto que la cerveza que fue fertnentado con el afrecho no tratado.