Although the nature and flavour of sourdough bread is in its name (it is, typically, sour!), this is far from a comprehensive description of the flavour profiles found within the bread. While there can obviously be various different types of sourdough, made in myriad ways, there is always something that signifies that it belongs to this popular class of bread.

Now, scientists from the Professorship for Food Chemistry and Molecular Sensory Science at the TUM School of Life Sciences in Germany have identified what this is, by identifying the taste-active compounds of sourdough bread crumbs.

The scientists used a variety of different techniques to decode the ten main flavours and eleven fragrance odourants that are distinctive of sourdough bread.

“We hope our findings and the quantification method we developed will help bakers achieve consistent quality in their sourdoughs. For example, they can prevent the bread from becoming too sour,” said Laura Eckrich, first author of the paper, who worked on the project as part of her doctoral thesis.

The study found that the essential taste components of sourdough are: potassium, sodium, chloride, magnesium, ammonium, d-fructose, calcium, l-glutamic acid, lactic acid, and acetic acid.

In a statement, the scientists who worked on the project wrote, “For the first time, the present method enables a unified high-throughput quantitation of the volatile key odorants and the non-volatile key tastants [chemicals that produce taste sensations] of sourdough bread crumb with the same instrumental setup. This method can be used to create a blueprint of the valuable aroma and taste compounds of breads to be independent of sensory tests in the future, especially during the industrial production of breads, and to obtain objective statements on the aroma and taste quality of breads.”