Researchers Uncover the Precise Components of an Ideal Homemade Sourdough

Sourdough bread is renowned for its crusty exterior and chewy interior. During the coronavirus lockdown, many people, including celebrities like Jake Gyllenhaal and Khloe Kardashian, attempted to perfect their own loaves. While the bread itself is made from only three ingredients—flour, water, and a bit of salt—there are chemical compounds that contribute to its complex flavor and unique scent.

A team of scientists at the Technical University of Munich in Germany has conducted a study to uncover the 21 essential chemical compounds that give sourdough its tangy taste and sweet, mild vinegar smell. These compounds include salt and lactic acid for taste, as well as molecules that resemble the aroma of butter and fresh-cut grass. The researchers believe that this newfound knowledge can help artisan bakers create more consistent and enjoyable sourdough bread for their customers.

A team at the Technical University of Munich in Germany has now used science to uncover the 21 essential chemical compounds that give the bread its tangy taste and the sweet, mild vinegar smell

Traditional sourdough is made using a “starter culture,” which consists of flour, water, and naturally occurring lactic acid bacteria and yeasts. These microorganisms act as raising agents and cause the dough to grow. The starter is then combined with more flour, water, and salt, and undergoes a series of reactions over the course of one to three days before being baked into a loaf.

In their research, the scientists delved deeper into the compounds at work in sourdough bread. They identified 10 key taste compounds and 11 key aroma compounds that combine to create a sourdough “essence.” Salt, acetic acid, and lactic acid were found to be crucial for the distinct sour taste. Other taste compounds included potassium for bitterness, as well as ammonium, chloride, magnesium, calcium, d-fructose, and l-glutamic acid.

Millions of people attempted to perfect the loaf during the coronavirus lockdown, including many celebrities like actor Jake Gyllenhaal

The aroma compounds include acids with cheese-like smells, acetic acid, butyric acid, 3-methyl butyric acid, and vanillin (which gives a hint of vanilla). The researchers also identified compounds like hexanal, which produces the scent of fresh-cut grass, and 2,3-butanedione, which has a buttery aroma. Additionally, phenylacetaldehyde contributes a sweet honey-like scent, while 3-methyl butanal offers fruity or cocoa notes, and methional and (E)-2-Nonenal provide vegetable or cucumber scents. The nutty aroma comes from decadienal.

To uncover these hidden wonders, the team used an updated version of a sensory technique called “sensomics” on sourdough bread crumbs. Sensomics is a cutting-edge scientific concept that allows the molecular analysis of natural flavors. By employing techniques such as chromatography and mass spectrometry, they were able to isolate and identify the flavor compounds in the bread crumbs and determine their significance.