You are using an old browser that may not function as expected.
For a better, safer browsing experience, please upgrade your browser.

Log in Become a Member

Crabtree effect

The French scientist Louis Pasteur (1822-1895) reported as early as 1861 that yeasts consume much less sugar during fermentation in the presence of oxygen, i.e. in an aerobic environment, than in an anaerobic environment. However, at higher concentrations of glucose (grape sugar) in the grape must from about 100 mg/l, ethanol (alcohol) can also be formed in the presence of oxygen. The phenomenon is called the "Crabtree effect" (also Pasteur effect or glucose effect) after the English biochemist Herbert Grace Crabtree. Genetic engineering could be used to develop effect-enhancing yeasts. At low glucose concentrations in the grape must, yeasts directly metabolise the sugar in the presence of oxygen, i.e. it is not converted into alcohol. In Geisenheim, attempts are being made to convert the glucose present in the grape must into gluconic acid by means of the enzyme glucose oxidase. Gluconic acid cannot be converted into alcohol by the yeasts. Similarly, experiments are also being carried out with the selection of ineffective yeasts. These methods are used to produce wines with lower alcohol content with the aim of improving the taste. See alcohol reduction for more details.

Voices of our members

Andreas Essl

The glossary is a monumental achievement and one of the most important contributions to wine knowledge. Of all the encyclopaedias I use on the subject of wine, it is by far the most important. That was the case ten years ago and it hasn't changed since.

Andreas Essl
Autor, Modena

The world's largest Lexicon of wine terms.

26,115 Keywords · 46,881 Synonyms · 5,323 Translations · 31,449 Pronunciations · 188,283 Cross-references
made with by our author Norbert F. J. Tischelmayer. About the Lexicon