Narziß:Title: Olive Oil Addition to Yeast as an Alternative to Wort Aeration
Abstract: To extend the flavor stability of their beers, many breweries are researching ways of reducing oxygen ingress throughout the brewing process. However, the practice of aerating the wort prior to fermentation is almost universal in the brewing industry because oxygen is necessary for yeast health and growth.
Recent studies have shown that alternative methods to traditional wort aeration such as aeration of the yeast prior to pitching or the addition of the unsaturated fatty acid linoleic acid can yield fermentation characteristics similar to wort aeration. It has also been shown that using these alternative methods instead of aerating the wort can reduce oxidation potential.
This presentation reports the findings of a series of full-scale production tests that were conducted in an operating brewery to evaluate the effects of another type of yeast treatment. By mixing olive oil into the yeast, during storage, instead of aerating the wort, fermentations can be achieved with only minor increase in fermentation time.
The beers produced from these fermentations were comparable in flavor and foam retention to beers produced by traditional wort aeration. The ester profile of the beers produced using olive oil addition was significantly higher than the controls and the flavor stability of these beers was significantly improved.
C.V. - Brief:
Grady Hull graduated from Colorado State University in 1994 with a BS in Food Science and Technology. After an internship with Coors Brewing Company he worked as a brewer for CooperSmith's and Fleetside brewpubs. In 1996 he began working at New Belgium Brewing Company where he is currently the Assistant Brewmaster. While working at New Belgium he received his MS in Brewing and Distilling from Heriot-Watt University.
VG, MarkusSauerstoff ist zwar für die Vermehrung der Hefe nicht unbedingt notwendig, wenn H2-Acceptoren (z.B. ungesättigte Fettsäuren) vorhanden sind, andernfalls kommt die Vermehrung allmählich zum Erliegen, wenn der Speicher an Purin- und Pyrimidinbasen aufgebraucht ist. Der Sauerstoff mag die Vermehrung jedoch zu beschleunigen, während CO2 eine hemmende Wirkung hat.
