He was born in Munich, the son of a physician and Professor Extraordinary of Forensic Medicine. In 1884, he began studies in chemistry with Adolf von Baeyer and in botany with Professor C. von Naegeli, at the Botanic Institute in Munich. After a period working with Otto Fischer in Erlangen, he was awarded a doctorate from the University of Munich in 1888.
Buchner married Lotte Stahl in 1900.
Buchner was awarded the 1907 Nobel Prize in Chemistry for his biochemical investigations and his discovery of non-cellular fermentation.
During World War I, Buchner served as a Major in a front-line field hospital at Focşani, Romania. He was wounded on August 3, 1917 and died of these wounds nine days later in Munich.
Buchner's experiment for which he won the Nobel Prize consisted of producing a cell free extract of yeast cells and showing that this "press juice" could ferment sugar. This dealt yet another blow to vitalism by showing that the presence of living yeast cells was not needed for fermentation. The cell free extract was produced by combining dry yeast cells, quartz and kieselguhr and then pulverizing the yeast cells with a mortar and pestle. This mixture would then become moist as the yeast cells' contents would come out of the cells. Once this step was done, the moist mixture would be put through a press and the resulting "press juice" had glucose, fructose, or maltose added and carbon dioxide was seen to evolve, sometimes for days. Microscopic investigation revealed no living yeast cells in the extract. One interesting thing is that Buchner hypothesized that yeast cells secrete proteins into their environment in order to ferment sugars, instead of the fermentation occurring inside the yeast cells which is how it really occurs.