No, it doesn’t have to be sour: debunking sourdough myths
Sourdough is increasingly popular in the UK, with Puratos research showing a strong 38% increase in sourdough-containing products between 2018 and 2023 (source: Taste Tomorrow, Puratos proprietary research, 2023). While there’s no doubt consumers enjoy it, many retain a narrow conception of its taste and the diversity of its applications.
Sourdough September provided the perfect time to dispel the myths surrounding sourdough, particularly that all sourdough tastes sour. In this article, we’ll explore how different flours influence flavour and explain the science behind fermentation’s impact on taste. By delving into how the fundamentals influence flavour, we’ll provide valuable inspiration for bakers and food producers keen to develop unique sourdough products that meet diverse consumer preferences, and capture new market opportunities as they drive baking industry innovation.
The bitter truth: debunking sourdough’s tart reputation
Historically, bakers strived to avoid excess sourness in bread because people prefer sweeter and more fragrant flavours. The perception of sourdough actually being sour emerged in the 20th century as bakers sought ways to manufacture bread as it was historically, but there was limited documented knowledge about traditional sourdough production methods.
The quest for a historic sourdough led bakers to German literature, which described very sour sourdoughs used for rye breads. High acidity is crucial for this type of bread as it helps create the correct texture by inhibiting the activity of certain enzymes, but it’s not as critical for wheat-based breads. The misapplication of this technique to wheat breads resulted in the overly sour taste many associate with sourdough today. In reality, sourdough can offer a spectrum of flavours, from mild and creamy to complex and tangy, without necessarily being sour.
Microbial alchemy: how fermentation creates flavour
Sourdough’s complex flavour profile stems from the intricate interplay of microorganisms within the starter. Wild yeasts and lactic acid bacteria work together to break down flour’s carbohydrates and proteins to leaven the dough as they generate diverse flavour compounds.
Consider the microbial ecosystem of sourdough as a pyramid. At the apex are dominant species, which largely determine the
sourdough’s primary characteristics. The middle layer consists of sub-dominant microorganisms, contributing additional flavour nuances. At the base, we find ‘satellite’ microorganisms – less prominent but crucial players in developing sourdough’s subtle flavour notes.
The concert of this microbial hierarchy together produces a wide spectrum of tastes and aromas. For instance, lactic acid bacteria contribute to the mild, yoghurt-like tang in some sourdoughs. Meanwhile, acetic acid bacteria can impart sharper, vinegar-like notes. Yeast fermentation produces alcohol-derived compounds that contribute fruity or floral notes.
There are as many as 1,500 strains of bacteria and yeasts in sourdough starters from around the world that can provide a strong foundation for diverse flavour development (Puratos sourdough library research, 2022). Bakers can manipulate factors such as flour type, hydration levels and fermentation conditions to influence which microorganisms thrive, creating baked goods with unique tastes that entertain and delight the palette.
Flour power: the foundation of flavour
From white to whole wheat, from rye to buckwheat, the type of flour used in sourdough has significant impact on its final taste by influencing the fermentation process. A sourdough made from whole wheat flour can be compared to fine wines that blend multiple grape varieties, with each element contributing a unique tonality that ultimately creates a complete flavour experience: deep, bodied and rich. In contrast, white flour produces a less complex sourdough with simpler flavour notes, perhaps more akin to a single-varietal wine.
The flour’s protein content also plays a crucial role. Higher protein flours, typically used for bread, can result in more robust flavours due to the increased availability of amino acids for bacterial fermentation. Lower protein flours, often used in pastries, may yield more subtle sourdough tastes.
Time and temperature: natural forces are the secret ingredients
While flour forms the base, time and temperature act as crucial flavour modulators in sourdough production. Fermentation time determines flavour, with shorter periods creating lighter, fruiter notes including berries and banana, while longer fermentation periods bring out more depth, intensity and acidity.
Meanwhile, temperatures affect flavour depth. Higher temperatures tend to favour lactic acid production, resulting in a milder, creamier taste, while lower temperatures can enhance tartness and tang.. We’ve found that temperature variations of just 5°C can significantly alter the microbial composition of a sourdough starter, leading to noticeable changes in flavour profile (Journal of Applied Microbiology, “Temperature effects on sourdough fermentation”, 2021).
The amount of sourdough used also plays a crucial role. A smaller amount will need longer fermentation time, therefore delivering more sour tastes. Higher amounts of a young sourdough (used between four and six hours after feeding) with a low amount of organic acids will deliver complexity and depth without the typical sourness many people associate with sourdough.
Bread is just the beginning: sourdough’s versatile applications
Sourdough is versatile and popular enough to create appealing products that go far beyond traditional loaves. Contemporary applications that include the appealing sourdough label could encompass sourdough cakes, with depth that balances sweeter flavours, or crackers that complete charcuterie and cheese boards with artisanal prestige. The possibilities for application innovation are as diverse as the sourdough flavours themselves.
The sourdough market has already seen significant diversification in recent years. While bread still dominates, accounting for 65% of sourdough product launches, we’re seeing increasing innovation in categories like crackers (12% of launches), pizza crusts and pasta (5% combined), and even in unexpected areas like cakes and pastries (8%) (Mintel Global New Products Database, Sourdough Product Launches 2020-202).
Consumers crave a world of flavours
Recent research indicates that consumer preferences for sourdough flavours are as varied as the sourdoughs themselves. A study of 100 panellists sampling six different sourdough profiles found no clear standout favourite. Instead, preferences ranged from roasted/malted (19%) to creamy (17%), fruity (16%), and various sour notes (15% each for sour/tangy and sour/toasted) (Good Sense Research on behalf of Puratos March – April 202).
Interestingly, the appeal of sourdough extends beyond taste. Our own Taste Tomorrow research has found that 71% of consumers believe food made with local ingredients has a positive environmental impact (Taste Tomorrow, Puratos proprietary research, 2023). Manufacturers have an opportunity here to not only diversify flavour profiles but also to highlight the local origins of the sourdough ingredients.
The sourdough library: a hub for flavour innovation
The world’s only Sourdough Library in Sint-Vith, Belgium, serves as a unique resource for understanding and preserving sourdough diversity. Housing 156 sourdoughs from 32 countries, each sample in the library represents a microbial time capsule of local baking traditions.
Our research at the library has uncovered fascinating insights into sourdough flavour development. For instance, we’ve found that sourdoughs from different regions can exhibit distinct flavour characteristics. Central European sourdoughs often showcase strong cereal notes, while samples from other areas may present more fruity or lactic profiles.
These findings have practical implications for manufacturers. By understanding how geography and local ingredients influence sourdough characteristics, bakers can create products with unique, regionally-inspired flavour profiles. This ongoing research, conducted at the Puratos Sourdough Institute, provides manufacturers with a wealth of knowledge to inform product development. By leveraging these insights, bakers can create innovative sourdough products that not only taste exceptional but also tell a unique story of tradition and scientific discovery.
Embrace sourdough’s complexity to tell compelling stories of innovation informed by tradition
For bread and bakery manufacturers looking to take their sourdough offering to the next level, these tips will inspire delicious, innovative products that draw on heritage, providing built-in narratives that support marketing efforts:
1. Experiment with flours. Each flour contributes unique characteristics to sourdough. Explore beyond wheat, incorporating popular ancient grains or pseudocereals like buckwheat or quinoa, which can create rich flavours reminiscent of cooked sausage or cheese.
2. Control fermentation variables. Precisely manipulate time and temperature to achieve desired flavour profiles. Remember, longer isn’t always better – it depends on your target taste.
3. Go beyond bread. There’s a strong appetite for non-bread sourdough products that include sweet treats and surprising savouries like biscuit bars and pizza dough. Don’t be afraid to get creative.
4. Leverage expert knowledge. Collaborating with sourdough specialists and research institutions can help navigate the complexities of sourdough production and accelerate innovation.
5. Tell your sourdough story. Consumers want to know where their food came from and how it was made. Craft a compelling narrative by explaining where your sourdough came from, what inspired it and the process you followed.
6. Invest in consistency. While sourdough’s variability is part of its charm, consistency is key for commercial production. Invest in systems and processes that allow you to maintain consistent quality and flavour across batches.
Sourdough September should be about celebrating contemporary science and using its insights to expand what we know about sourdough, to inspire more market diversity. The future of sourdough isn’t all sour, nor is it all bread-based. It’s about recontextualising a historic heritage in exciting ways to create baked goods with appealing textures and complex flavours that come from carefully managed fermentation. The sourdough market, already seeing significant growth and showing no signs of slowing down, presents ample opportunities for those willing to explore its depths and reach new heights.
