The world of bread is endless, branching out into a wealth of textures, recipes and traditions. But its roots are quite simple. Puratos has discovered that sourdough has terroir, just like cacao and wine. 

It all starts with flour, water and fermentation with sourdough. For centuries this has been bread’s seed of life, yet its simplicity is deceiving. Thousands of different wild yeasts and lactic bacteria thrive in it, each bringing its own characteristics and creating its own flavour. And once these sourdoughs are added to dough, their complexity only increases. To chart these traditions and unlock sourdough’s full potential, Puratos embarked on a ‘Quest for Sourdough’ around the world. And now they’re back with a freshly baked set of unexpected insights.

The Sourdough World Map

Chocolatiers know that cacao has different flavour profiles depending on its terroir. Yet, until now it was unknown to bakers if the same could be said about their most important ingredient, sourdough. Thanks to the Quest for Sourdough, and all the people that participate, we are finally able to map the different flavours of sourdough around the globe.

How does it work?

On the Quest for Sourdough website, people can register their own, homegrown sourdough. And to date, more than 1700 people have been inspired to do just that. The online sourdough collection they have built is remarkable, ranging from sourdoughs that are over a century old to specimens that have been started with coffee beans. And they can be either rock solid or take the shape of a living, breathing kind of soup.

Out of these 1700 people, over 1300 made the effort to describe the flavour profiles of their sourdough starter by ranking the level of ‘fermented’, ‘roasted’, ‘cereal’, ‘fruity’, ‘lactic sourness’ and ‘acidic sourness’ flavour on a scale from 1 to 10. And the results provide us with insights that lift our research to another level.

What did we find out?

Today, the Quest has resulted in a one-of-its-kind Sourdough World Map, showing the two most prominent sourdough flavours in dozens of countries across the globe. And with each continent having different flavour profiles, there’s plenty of data to gather.

On analysis, it seems that specific flavours are indeed linked to a particular region. A clear example is the very prominent presence of cereal sourdough flavours in Central European countries like Germany, Poland, Czechia, Slovakia and Switzerland. It’s a flavour that relates to the flour used in the sourdough. Flours like rye and spelt for instance have strong flavours that stay present in the sourdough. ‘Fermented’ and ‘lactic’ are the most common dominant flavours to be found. The reason behind this lies in sourdoughs’ microflora. Different wild yeasts that naturally exist around us in the air and in flour also live inside the sourdough.

As they thrive, they change its aroma into one that’s also commonly found in other fermented foods like wine and kimchi.

Lactic bacteria live together with these wild yeasts. It’s these bacteria that contribute to the endless flavour complexity. On Quest for Sourdough, I’ve read the most fantastic descriptions of people’s sourdoughs. There’s someone from Belgium who describes the flavour as “buttery, candy-fruity and caramel”.

Another person in Singapore states his sourdough has “a lovely banana aroma” and again someone else in Brazil saying her sourdough has a combination of “lactic, and sweetness”.

All these different flavours can be explained by the behaviour of all these different lactic bacteria. Just like everything else that is alive, microorganisms are influenced by factors such as temperature, humidity, and time. All these factors make sourdough perhaps the most complex ingredient in the bakery world.

Acidic sourness, the type of sourness you can find in vinegar or lemon juice, is almost nowhere to be found as a prominent dominant flavour in sourdough. How come an ingredient that’s been named after the sour taste, has such different flavour profiles?

Many people know sourdough from the acidic San Francisco-style sourdough breads or the typical German ‘sauerteig’, but in many cultures, there is no link with sourness. The French for instance say ‘levain’, which means ‘leavening’, and the most beautiful name for sourdough comes from Spain, where they say ‘massa madre’, literally: mother dough.

What’s next?

The discovery that sourdoughs have different flavours across the world won’t be our last.

At Puratos, we see sourdough not only as an ingredient to bring about different flavours, but also as a technique to bring more character, texture and better digestibility to breads. In the end, it’s all about baking the best.