Saccharomyces pastorianus#Saccharomyces uvarum

Lager yeast (Saccharomyces uvarum and Saccharomyces carlsbergensis ) is a hybrid form of traditional brewer's yeast. Today only yeasts are used. After fermentation, the yeast is lowered to the bottom of the fermentation vessel, hence the name. The lees is called in the jargon as " strangles " or " lees ".

Lager yeast is required as opposed to top-fermenting yeast a low room temperature ( 4-9 ° C) for fermentation. As a result, fewer fungi and microbes can multiply in beer brewing, so that the bottom-fermented beer brewed distinguished against the top-fermented by a higher durability. In addition, the bottom-fermenting brewing requires a longer fermentation and storage time.

History

Until the 15th century in Europe only the top-fermenting yeast Saccharomyces cerevisiae was known. Today's bottom-fermenting brewer's yeast was created by a mixing of this yeast with a wild yeast species from Patagonia, Saccharomyces eubayanus.

Before the invention of refrigeration machine in 1876 by ​​Carl von Linde was dependent for the lager brewing on natural low temperatures. These were cut in winter from frozen waters Eisklötze and stored away in these caves and deep cellars ( icehouse ). This the fermentation tanks was then used for cooling when the ambient temperatures for brewing were already too high.

So it is to explain that the lager brewing in areas with severe winters, has a long tradition. Its origin lies in the Upper Palatinate, where they probably arose in the 15th century. 1487 committed the City Council Nabburg its breweries to brew only bottom-fermented beer. The bottom-fermenting brewing way initially spread across the rest of Old Bavaria and soon beyond. In the 16th century Bavaria and Württemberg were the only areas where it was already brewed almost exclusively bottom-fermented. Today, the lager brewing is the dominant brewing.

Typical fermenting are: Pils, Export, bock beer, Märzen, storage, gussets, Zoigl

It is necessary that the yeast leads to the use of the fermentation, is also examined biologically. The breweries have this operation inspectors who are either university education ( Weihenstephan, VLB Berlin) or brewmaster schools. To avoid any contamination, are also sent samples to the respective universities, brewmaster schools or other labs.

To control the yeast, samples are taken from her, either immediately examined microscopically or enriched on nutrient media and by visible change in the medium already visually ( with the " naked eye " ) or again examined under the microscope. This is the responsibility of the biological control operation (not only in terms of yeast) used in brewing is important for many other controls. In the 1960s and 1970s was a spurt in the development of the overall operation control, not only of the biological. This led to the current high quality, especially the bottom-fermenting beers. One then just emerging culture medium for the detection of beer spoilage was the Japanese Nakagawa- medium was also studied in Germany by Klaus Grunenberg and modified in part.

Swell

  • "Brewing Science " Volume 28 / Issue 6 WP Hsu, JA Taparowsky and M. W. burner
  • A. Nakagawa, " A Simple Method for the Detection of Beer - Sarcina ," Bull.Brew.Sci (Tokyo) 10 7-10, 1964
  • K. Grunenberg: "Fast determination of beer spoilage " World of Brewing 115, 46-48, 1975
Saccharomyces pastorianus
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