International sourdough library keeps cultures alive

The Puratos sourdough library specializes in strains of naturally fermented yeast cultures from around the world. This unique library houses samples of flour, water and starter from various countries, in an attempt to research the global biodiversity of sourdough bread.

The wood-panelled library features a forest canopy on its ceiling, emphasizing its natural interest in organic matter. It stores over 100 specimens of sourdough cultures and refreshes each one with local flour and additional ingredients directly from its specific region.

For bakeries to have their starters preserved for posterity on the shelves of the Puratos sourdough library, each inductee is asked to provide the ingredients needed to keep the cultures alive. Each inductee must provide local flour and additional specific ingredients from their region in order to feed the starter.

Sourdough librarian, Karl De Smedt is excited about this project, as it allows researchers to locate certain strains of yeast not only by region, but also by latitude. Several different micro-strains and properties of flour can also be filed and catalogued from around the world.

Of particular interest, de Smedt has found a strain of benevolent bacteria from a culture extracted from a bakery in the Swiss alps that was nearly identical to a strain found in Chile. In this particular case, de Smedt hopes other bakeries at the same latitude will come forth with their sourdough strains, in order to help add data to the study of latitude on the effect of bread-making.

Karl de Smedt, Sourdough Librarian


Toronto bakery, Blackbird Baking Company is the first Canadian bakery to have its sourdough culture inducted into the Puratos sourdough library. The bakery is based out of Kensington Market and known for its sourdough breads, unique flavour and of course, it’s sourdough starter.

Puratos welcomes viewers to tour the virtual sourdough library: www.bit.ly/PuratosVirtualLibrary.

If you have any sourdough or bakery-related questions, you can reach Karl de Smedt via Instagram @the_sourdough_librarian.