Register for free to listen to this article
Thank you. Listen to this article using the player above. ✖
Want to listen to this article for FREE?
Complete the form below to unlock access to ALL audio articles.
By submitting your email address, you agree to receive email communications related to Technology Networks content, products, or our partners. You may unsubscribe from these communications at any time as we respect your privacy. View our Privacy Policy for more information.
A staple of lockdown kitchens and bakeries across the world, sourdough is famed for its unique, tangy flavor. New research, presented at the American Chemical Society (ACS) Fall 2023 conference, has identified what makes sourdough taste so good.
The importance of the starter
The wild yeast and microbes found in the starter of a sourdough cause the bread to rise by consuming the carbohydrates in the flour and producing carbon dioxide, which gives the bread its characteristic airy texture. Early sourdough research revealed that over 50 types of lactic acid bacteria and over 20 species of yeast can thrive in sourdough starters.
As the starter uses wild yeast and microbes, starters across the world can vary. San Francisco is particularly famed for its sourdough, with some bakeries using the same starters in their recipes for around 170 years. It has been rumored that the foggy environment of the city plays a role in the taste of the sourdough, with the loaves once thought to contain a unique bacterium dubbed Lactobacillus sanfranciscensis, which was later found across the world.
The essence of sourdough
The taste of sourdough can be influenced by factors including fermentation time, temperature and flour type, as well as the microbes present in the starter.
A research team has identified the compounds responsible for sourdough's unique taste, finding 11 odorants and 10 tastants using a technique called sensomics.
“With sensomics, you can take just a few key compounds and completely recreate the characteristic taste of a food,” said Laura Eckrich, who presented the team’s research at ACS Fall 2023.
Sensomics uses data from chromatography, mass spectrometry and other techniques to isolate and quantify key molecules from food – in this case, the crumb of the sourdough – enabling researchers to piece together the food’s “essence”.
Want more breaking news?
Subscribe to Technology Networks’ daily newsletter, delivering breaking science news straight to your inbox every day.
Subscribe for FREE
The sourdough essence was then confirmed to match the smell and taste of sourdough bread by a human sensory panel.
The key tastants in sourdough include salt, acetic acid and lactic acid. Salt is added to the loaves by the baker, but acetic and lactic acids are the byproducts of fermentation. The researchers then compared the concentrations of these compounds in sourdough with yeast-based breads, made with either rye or wheat flour.
Although yeast-based breads did contain lactic and acetic acids, they were present in much lower concentrations than in sourdough, confirming the importance of the fermentation process for developing flavor in a sourdough loaf.
Of benefit to bakers
This new research could help bakers control the quality and consistency of their loaves and prevent waste from loaves that are too sour. It can also help optimize the amount of salt bakers add to their sourdough.
“This was the first time the key taste and aroma compounds of bread crumb were elucidated using the sensomics approach, and we hope what we learned will help bakers create the best sourdough breads they can,” said Eckrich.
Reference: Amann LS, Frank O, Dawid C, Hofmann TF. The sensory-directed elucidation of the key tastants and odorants in sourdough bread crumb. Foods. 2022;11(15):2325. doi: 10.3390/foods11152325
This article is a rework of a press release issued by The American Chemical Society. Material has been edited for length and content.
FAQs
The key tastants in sourdough include salt, acetic acid and lactic acid. Salt is added to the loaves by the baker, but acetic and lactic acids are the byproducts of fermentation.
Why does sourdough bread have a distinct taste? ›
Bacteria, colored blue, metabolize sugars and release byproducts such as lactic acid and acetic acid. These byproducts act as a preservative and are what give the starter its distinctive sour smell and taste.
What's so special about sourdough? ›
Sourdough relies on a mix of wild yeast and lactic acid bacteria, rather than baker's yeast, to leaven the dough. It's richer in nutrients, less likely to spike your blood sugar, contains lower amounts of gluten, and is generally easier to digest than bread made with baker's yeast.
Why does sourdough bread have a unique taste and chewy texture? ›
The long, slow fermentation process that sourdough requires allows the yeast and bacteria to break down the proteins in the flour, making it easier to digest and giving the bread a chewy texture. In addition to contributing to the flavor and texture of sourdough bread, the yeast in sourdough has other benefits as well.
What gives sourdough bread its unique flavor? ›
Sourdough bread's signature taste comes from friendly bacteria and yeast, which produce flavorful lactic and acetic acids in rising bread dough.
Why do people like sourdough bread so much? ›
As one of the healthiest breads, sourdough is well-liked due to its nutritional benefits. The natural yeast in the sourdough starter breaks down a substance naturally found in wheat that can block our bodies from absorbing its nutrients.
Why is everyone making sourdough bread in 2024? ›
For many folks, the renewed interest in sourdough is health-related. Some are going even further than baking their own bread: They're milling their own flour from whole wheat berries, too.
Is it okay to eat sourdough bread every day? ›
Health benefits of sourdough. The type of flour used — all-purpose, whole wheat, rye — can affect the nutritional content of sourdough bread, says Wee. But generally speaking, sourdough bread is a healthy option and can be eaten regularly as part of a nutritious, balanced diet.
Is sourdough bread anti-inflammatory? ›
The best bread to reduce gut inflammation is bread made from whole grains. Refined grains, such as the grains found in white bread and white pasta, are known to increase inflammation across the whole body. Sourdough bread and rye bread are both good options for an anti-inflammatory diet.
Is sourdough actually healthier? ›
The fermentation process and higher fibre content makes sourdough a useful option for those with blood sugar management issues. This is because, unlike many commercially produced breads, sourdough has less of an impact on blood sugar levels.
Sourdough uses very few ingredients. In fact, a basic sourdough bread contains just flour, water and salt. If you're not in the 33% of the nation that's considered making sourdough in the last year, you may be wondering where the yeast is… This is one of the reasons sourdough is so great.
What does Overproofed sourdough taste like? ›
A very sour taste (not a pleasantly sour tang like properly fermented sourdough) A sour/fermented smell. You might notice a “corn” flavor to the baked crust (sometimes there is a faint odor like popcorn) Crust may have small tears in it, randomly over the surface.
How to make sourdough bread taste better? ›
For bread with stronger sour flavor, the preferment should be:
- Looser (100% to 125% hydration), rather than stiff (see “a cautionary note,” below)
- Ripened at a higher temperature (75°F to 82°F)
- Fed a larger meal; rather than 1:1:1 (starter:water:flour), the feeding ratio should be more like 1:4:4 or similar.
Sourdough is naturally leavened bread, which means it doesn't use commercial yeast to rise. Instead, it uses a 'starter' – a fermented flour and water mixture that contains wild yeast and good bacteria – to rise. This also produces the tangy flavour and slightly chewy texture you'll find in sourdough.
What is the secret to sourdough? ›
The secret to sourdough is simple: water. The more water you add to your dough will affect how open the crumb (bigger holes and softer texture) will be once it's baked.
What makes sourdough taste so good? ›
The key taste compounds include salt, which is directly added to the dough, as well as acetic and lactic acid, produced during fermentation. After these experiments, they applied a technique called “unified flavor quantitation,” which was previously developed by Hofmann's team, to the sourdough bread.
Does sourdough taste different than regular bread? ›
The flavor of sourdough is more complex than regular bread because it contains lactic acid, which gives sourdough bread a tangy, even sour taste which sometimes people with GERD condition couldn't consume it. Though, if you are looking for a sweeter and more convenient taste most regular bread will serve it for you.
How does sourdough bread get its sour taste? ›
There are two main acids produced in a sourdough culture: lactic acid and acetic acid. Acetic acid, or vinegar, is the acid that gives sourdough much of its tang. Giving acetic acid-producing organisms optimal conditions to thrive and multiply will produce a more tangy finished product.
What does real sourdough bread taste like? ›
The inside of the bread should be bubbly and chewy and the bread should have a slightly tangy taste. Real sourdough bread does not contain additives like oil, milk, corn, and dough conditioners. It is made with whole grains and is generally more expensive than regular bread.
Why is the taste of San Francisco sourdough so distinctive? ›
Some say the foggy climate gives San Francisco's sourdough bread a special bounce, and others say it's a specific local strain of yeast that gives the characteristic flavor. That bounce and flavor are notes that pair perfectly with a California Chardonnay or Chenin Blanc.
