Eduard Buchner Demonstrates Cell-Free Fermentation

In 1897, German chemist Eduard Buchner demonstrated that alcoholic fermentation could occur without intact, living yeast cells. Buchner ground yeast with quartz and kieselguhr, pressed the mixture, and obtained a cell-free liquid from the disrupted cells. When sugar was added to this yeast press juice, it produced alcohol and carbon dioxide even though microscopic examination found no living yeast cells. The experiment showed that fermentation depended on soluble biochemical substances within yeast rather than requiring the activity of the complete living organism. Buchner called the active fermenting complex zymase, and his work became a foundation of enzymology and modern biochemistry. The discovery deepened scientific understanding of the reactions performed by brewing yeast and earned Buchner the 1907 Nobel Prize in Chemistry.