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Th e w i n e e s t a t e a n d w o rk i n t h e v i n e y ar d Chr i st i a n G ö l d e n b o o g

e with and without oxygen Th e h i s t o r y o f a l c o h o l i c f e r m e n t a t i o n a n d s p o n ta n e o u s f e r m e n tat i o n Cells or organisms need energy from external sources in order to survive. Plants like vines use the energy of sunlight; many animals get the necessary energy by feeding on plants. Other animals live on herbivores. The life of fungi and animals, and naturally also the life of man is dependent on oxygen. More precisely: complex metabolic processes release energy only when oxygen is involved by breaking down complex molecules into simpler combinations. The so-called cell respiration or internal respiration is the most important and also most efficient metabolic process, which produces energy: in this process glucose as well as other organic matter from food is broken down in such way that the stored energy is made available by the resulting molecules for the work of the cells. A further result of all these processes, which are precisely co-ordinated and can be compared to a miniature factory regarding their sequences, is carbondioxide and water. In addition, energy goes only in part towards the cellular processes the rest is lost as heat energy. However, surprisingly there are organisms which can live without cell respiration. Yeasts are among them. They, remarkably, process sugar molecules without the involvement of oxygen when converting energy. And it is precisely this that is understood as fermentation in modern biology and biochemistry. First to recognise this was the French microbiologist Louis Pasteur. There are many kinds of fermentation and they all produce different results (differing by their specific end products): ethanol, thus ethyl alcohol, as well as carbon dioxide, are a by-product of alcoholic fermentation. Lactic acid fermenta-

tion produces lactates. This type of fermentation, triggered by certain bacteria or fungi, is also used by man to produce food, such as cheese or yoghurt. Even man himself can act as a fermentation vessel – in certain situations! If we compete in a half marathon the morning after a night of heavy drinking, the muscle cells switch over to lactic acid fermentation as soon as the oxygen supply to our muscles from our blood can’t keep surprisingly there up with the energy demand. They then get their energy are organisms which with­out oxygen supply while can live without cell lactates build up in the muscle. In 1904 the chemist Franz respiration Lafar wrote his “Handbuch der technischen Mykologie” (Manu­al of technical mycology) on “gären” (­fermenting) – this fine ­German word – in it he states that “gären” derives from the Middle High German “gern” (with pleasure), and this in turn from the Old High German “Jerian”. However, the origins of this word are to be found in the Sanskrit expression “Yastas”, which in turn bears a striking resemblance to the English word “yeast”, i.e. German “Hefe”. Lafar goes on to explain that the term “Gärung” is based on the expression “gar ab”, meaning an unfinished product that requires further processing before being ready for consumption. Pressed juices from fruit sometimes begin to ferment spontaneously if not drunk imme­diately. The same happens to watered down honey;

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Riesling - Robert Weil  

This book covers the complex topic of Riesling through the fine example of the top German wine estate Robert Weil. For the last twenty years...

Riesling - Robert Weil  

This book covers the complex topic of Riesling through the fine example of the top German wine estate Robert Weil. For the last twenty years...

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