Celebrating 10 Years of Sourdough History: An Exciting Journey through the First Decade of the Sourdough Library!

Welcome to the beginning of an exciting journey! This year, we will discover a decade of Sourdough Library history.

Every month we will celebrate a different milestone in the Sourdough Library's inspiring journey since its inaugural opening in 2013. On October 18th, join us for an exciting online event from within our library as we commemorate ten great years of study and discovery!

In this newsletter, we talk about how it started, what and how we do it, and we show one of the studies we conducted on 37 Italian sourdoughs. But we will also have a flashback to the opening of the sourdough library. A movie recorded at that time will testify to that. And last but not least, some footage was made in Altamura. La Citta del Pane, or city of bread, where one of the better loaves of bread I have ever tasted comes from.

How it all started?

In 1989, our journey to explore the diversity of sourdough began with a single sample collected from a bakery in San Francisco. Five years later, I baked my very first sourdough bread with it and soon discovered how diverse this ancient art can be as we gathered 43 samples over two decades from four countries across the world. As some bakeries closed their doors for good, leaving us wondering about what happened to these timeless recipes or if they'd been replaced by commercial yeast - that's when it became clear: We must open up an exquisite library dedicated to protecting and preserving precious heirloom varieties of traditional sourdoughs!

One hundred thirty-nine bakers trust the library with their samples and recipe.

With a dedication to preserving the flavorful heritage of baking, Puratos Sourdough Library in Sankt Vith is committed to safeguarding some of the world's most treasured sourdough cultures. More than 130 bakers and sourdough lovers from far and wide have recognized this need for safekeeping and entrusted their unique creations with the library's care - understanding that these recipes are not only part of global taste history but represent their livelihood as well. It is heartening to see such passionate attention given to something fragile yet integral!

Preserving the biodiversity of sourdough.

In the sourdough library, we preserve the unique biodiversity of each sourdough for future generations. Prof. Marco Gobbetti and his team from the free university of Bolzano in Italy isolate these strains and store them at -80C to lock in their genetic identity; next to that, we analyze the DNA, which has so far revealed over 1500 different kinds of yeasts and lactic acid bacteria.

We are protecting baking heritage.

We are dedicated to protecting the art of baking for future generations by meticulously documenting each new sourdough that comes our way. From sourcing out who made it, how it was crafted, and its key ingredients, such as flour type used - all the way down to age specifics, we strive towards capturing every detail available to ensure a thriving time-honored tradition.

Offering a backup.

Having a physical sample of sourdough saved in our library proved invaluable when an employee used up all the mother dough needed for baking bread. Incredible as it may seem, this only happened once over the past decade - which is why its owner was understandably shocked and panicking on that Saturday morning he called us! We were able to quickly provide assistance by sending back some backup from our library collection, genuinely demonstrating how we are always ready with support should anything go wrong.

A snapshot of the study of Italian sourdoughs.

With a desire to unlock the secrets of Italy's century-old baking methods, we decided to explore sourdough cultures. We scoured far and wide across this beloved country - from southward in Sicily all the way north through Sardegna - collecting 37 samples, half for lean dough and the other half for soft and sweet applications like Panettone, along our journey with which to conduct further research. But what did those findings reveal? Here is but a glimpse at some of our discoveries...

Introducing the Study – Exploring Italy's Century-Old Baking Methods.

The remarkable results of this study demonstrate the significant impact that different types of flour and various concentrations of their nutrients have on selecting lactic acid bacteria in sourdoughs. Specifically, Triticum durum flours had higher levels of maltose, glucose-fructose, and Free Amino Acids, associated with obligately heterofermentative lactic acid bacteria. At the same time, most Triticum aestivum-based sourdoughs showcased facultatively heterofermentative lactic acid bacteria as its predominant microbiota population.

A sourdough's unique microbiome is crafted by the time, temperature, and proportion of its back-slopped inoculum. The most abundant LAB species identified were Lactobacillus sanfranciscensis (28%), Lactobacillus plantarum (16%), and paralimentarius (14%). Meanwhile, Saccharomyces cerevisiae was the dominant yeast, with Candida humilis, Kazakstania barnettii, and exigua completing a harmonious microbial composition.

Sourdoughs from two clusters (lean and sweet applications) differed mainly in their lactic acid bacteria cell density, organic acid concentration, and various strains present. Notably, a remarkable dominance (72%) of L. sanfranciscensis was observed for sweet baked goods sourdoughs due to certain technical factors and other intrinsic attributes suited for this environment. Other than that, multiple species existed, such as Lactobacillus plantarum, Leuconostoc citreum, Lactobacillus sp., Lactobacillus brevis, Lactococcus lactis among others, along with Saccharomyces cerevisiae which proved essential too.

By analyzing this assortment of organisms in their natural environment, new insight can be gained into environmental influences that shape specific sourdough microbiotas.

This study is a mere glimpse into sourdough's captivating, diverse world. A single exploration reveals only so much; what lies beneath its surface? The possibilities are endless, from different regions to various flour types and temperatures. What secrets will be revealed when we delve deeper into these uncharted starters?

A flashback to 2013! The moment we inaugurated the library.

On October 15th, 2013, a historic event took place. An exciting moment for 250 participants from 29 countries who had come together to witness history being made when Eric Kayser from Maison Kayser donated his two starters into what would soon become known as the Sourdough Library. For two days, renowned speakers regaled and inspired those present, culminating with Dominique Persoone's ingenious dessert crafted using O-tentic Durum ice cream that none at this special gathering could have foreseen just how much potential this library held in its future ten years on!

My trip to Altamura. The first of my "Quest for sourdough" movies.

My movie about the Altamura bread is a must-watch for anyone who wants to learn more about this delicious and unique bread having its "DOP" or protected denomination of origin. This movie takes you on a fantastic journey, exploring the secrets behind the age-old process of creating this special type of bread. I had the chance to meet my friend Prof. Marco Gobbetti, who shared his fascinating insights on sourdough, as well as Fabio, who enlightened me on the use of Durum wheat flour, and Nunzio, who showed me how to craft a truly unique Altamura bread. It was truly an amazing experience, and I am excited to share it with you.

This is coming in the following newsletter.

The year 2014 has been quite the journey! From discovering unique sourdough in Greece to meeting renowned bakers from all over the world. I had a chance to meet some notable bread-makers like Michel Suas and Chad Robertson, as well as Tom Frainier at Semifreddi's and Steven Sullivan of Acme Bread. These experiences marked an exciting milestone for us in 2014. Not to mention the addition of 15 French sourdoughs to the collection.

Do not miss anything...

Do you have a specific question, feedback, or recommendation for one of the following newsletters? I would like you to comment below, send me a DM here on LinkedIn or follow me on Instagram.

Sincerely yours,

Karl, the Sourdough Librarian