Wine yeast

Dry wine yeast granules

Wine yeast is used to make alcoholic beverages (e.g. apple cider , ginger wine , mead or fruit wine ). The numerous strains offered in the trade as pure yeast differ in terms of the aromas they promote, the nutrient requirements, alcohol tolerance, the recommended temperature range, the tendency to foam, the fermentation process, the influence on malolactic fermentation and the preservation of color (red wine), etc. .

Natural occurrence and reproduction

In nature, yeasts occur wherever sugar solutions occur. The typical yeast strains are Saccharomyces cerevisiae , Saccharomyces bayanus , Saccharomyces ellipsoides and Saccharomyces uvarum . At the time of the grape harvest , the yeasts live on the surface of the ripe berries, especially in the microfine cracks through which the sweet grape juice seeps through. The yeast reproduce up to 35 times by sprouting cells, leaving scars on their surface, which damage the cell membrane until the cell dies. They need sugar as an energy source, as well as nitrogen , phosphorus , sulfur , carbon , oxygen , minerals and trace elements, most of which are present in grape must .

Wine yeast in the process of making wine

As soon as the juice pressed from the berries has fermented into wine and therefore no longer contains any fermentable sugar, the activity of the wine yeasts decreases. From a certain alcohol content (see pure yeast ) the complex process of autolysis begins . The yeasts die and sink to the bottom. During this process, the activity of enzymes releases components of the cytoplasm and the cell wall into the wine, which thereby gains in abundance and aromatic complexity (see also organoleptics ).

See also

• Yeasts
• Pure yeast

Web links

Commons : Weinhefe  - Album with pictures, videos and audio files

Wiktionary: Weinhefe  - explanations of meanings, word origins, synonyms, translations

literature

• Wolfgang Renner: Yeasts in winemaking: use, optimize, compare. Av Buch, Vienna 2005, ISBN 978-3-7040-2119-9 .
• Robert Steidl: Cellar economy. Av Buch, Vienna 2001, ISBN 978-3-7040-1699-7 .

Individual evidence

1. ↑ Martin Nagel  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF; 956 kB): Yeast propagation with high-gravity wort. Diploma thesis, Munich 2004, p. 5