Yeasts biology

The new edition appears as two volumes because a single one would be inconveniently bulky. The first volume outlines the entire process and leads from barley, malting and water to the production of sweet wort. In the second volume there are chapters on hops and hop products, production of hopped wort, fermentation, yeast biology and all aspects of beer qualities and treatment. 

Figure 9.3 Selected milestones that mark the path of research in microbiology and yeast biology that impacted wine science and winemaking directly or indirectly.

J. Broach, E. Jones, and J. Pringle, eds.. The Molecular and Cellular Biology ofithe Yeast S accharomyces Cold Spring Harbor Press, New York, 3 vols., 1991-1997. 

E. Sherman and P. Wakem in C. Guthde and G. Pink, eds.. Guide to Yeast Genetics and Molecular Biology, Methods in Engymology, Vol. 194, Academic Press, New York, 1991, p. 38. 

Filtering. Conditioning or 1 agering gives the beer its desired organoleptic properties, but it stiU contains yeast, protein-tannin complexes, etc, ie, it has a hazy appearance. A high quaHty beer must be clear and totaUy sterile, have coUoidal stabiHty, and yeast must be removed to aUow the beer to have biological stabiHty. The protein-tannin complexes must also be removed so as not to upset the coUoidal stabiHty. 

E. A. Skinner, Biology and Activities of Yeast, Academic Press, London, 1981. 

At 70—140°C, peroxide is vaporised. Peroxide vapor has been reported to rapidly inactivate pathogenic bacteria, yeast, and bacterial spores in very low concentrations (133). Experiments using peroxide vapor for space decontamination of rooms and biologic safety cabinets hold promise (134). The use of peroxide vapor and a plasma generated by radio frequency energy releasing free radicals, ions, excited atoms, and excited molecules in a sterilising chamber has been patented (135). 

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