Scientists of the TU Muenchen reveal the key flavors of bourbon whiskey

Whiskey is famous for its unique aroma combining smoky, malty odors with a characteristic sweet, vanilla-like flavor note, in particular, in American Bourbon-whiskeys. Over the last 40 years more than 300 volatile substances have been found in the scientific quest to unravel the flavor and aroma secrets of whiskey. Scientists of the Technische Universitaet Muenchen (TUM) now have isolated the key substances responsible for the distinctive bouquet of American bourbon whiskey. The findings can help producers to maintain quality or to vary the recipe or manufacturing processes in order to produce whiskey with special flavors.

The individual bouquet of a whiskey is the result of a vast number of chemical reactions influenced by ingredients, fermentation, distillation an aging processes. Peter Schieberle, head of the chair of Food Chemistry, and his group selected the key components from the more than 300 compounds that had been identified over the years by a special dilution technique, the aroma extract dilution analysis. They combined gas chromatography and mass spectrometry to identify the volatile compounds and the human nose to link each compound to its smell. As a result they could identify 42 of 45 substances - 13 of them for the first time.

Furthermore they conducted quantitative studies by stable isotope dilution assays to determine the exact concentration of the individual components in the spirit. "It is still not possible to completely synthesize a good whiskey", says Prof. Schieberle. "But our results help to understand the different processes and their contribution to the overall flavor, which is a key to maintaining a high quality."

Source: TU Munich