As of March 2020, in which country is the world’s only sourdough library?

Mr. Karl De Smedt is the curator of the world’s only sourdough library, located in the village of St. Vith, 87 miles southeast of Brussels. The library houses the world’s most extensive collection of sourdough ‘starters’, bubbling mixtures of bacteria and wild yeast — known as “mothers” — that bakers mix into dough to produce flavourful loaves.

Like Norway’s Svalbard seed vault, safeguarding crops against disasters, and the Ice Memory project in Antarctica, protecting glacial ice cores threatened by climate change, the sourdough library is a preservation centre conserves a burgeoning stockpile of yeast varieties for future generations to study. The library, created in 2013 by the Belgian bakery supply company Puratos, is not open to the public but its online database offers detailed notes on the colours, flavours and textures of all the starters. The samples serve as backups for bakers and bakeries that might lose or damage their own supply.

The walls of the library are lined with illuminated cabinets kept at 39 degrees Fahrenheit, filled with jars of a variety of starters refreshed every two months with back stocks of the original flours used by their providers. Up to two dozen new sourdoughs are added to the library every year, from cooking schools, home-bakers, pizzerias, artisan and industrial bakeries all over the world. Starters are unique to the environments in which they were created; no two sourdoughs taste exactly alike.