Sourdough Institute invites bakers to feed its living library in Belgium

The Sourdough Institute turned starter care into a living-duty call in St. Vith, where bakers were invited on June 2 and 3, 2026, to feed the cultures of the Sourdough Library by hand. This was not a drop-in tour. It was a two-day refreshment process built around preserving a collection that lives, changes and depends on regular care.

The schedule made that clear from the first hour. Day 1 began with a welcome and the first refreshment session, then moved into preparing the jars that would be used over the coming month. Participants came back for a second refreshment in the afternoon, then returned in the evening to refrigerate the refreshed jars. Day 2 opened with shared breakfast and a final refreshment session, with the work finished by lunchtime. The institute covered all costs related to the event and offered help with accommodation and transportation if needed, which signaled that this was aimed at serious bakers, researchers and fermentation people willing to take part in the upkeep, not just look at it.

That upkeep matters because the Sourdough Library is being treated as a collection of living fermentation communities, not a trophy case of old dough. Puratos opened the Sourdough Institute in June 2024 in Saint-Vith, Belgium, with a mission to “protect, research and inspire” sourdough culture through masterclasses, online events and scientific research. The company says the institute houses the world’s only Sourdough Library, located in the Center for Bread Flavour in Saint-Vith.

The library itself has been building for years. Puratos says it launched in 2013 with 43 sourdoughs and now lists 84 on its consumer site. It also says more than 700 strains of wild yeast and 1,500 lactic bacteria have been recorded so far. Industry coverage in 2024 placed the library at 153 sourdoughs and 1,500 isolated strains, a reminder that counting a collection this alive can depend on whether you are tracking jars, strains or both.

That is the real story behind the June feeding session. The Institute is not just preserving recipes or displaying bread culture in a vacuum. It is maintaining a shared microbial archive, one jar, one refreshment and one careful day at a time, so the library’s starter cultures keep their edge far beyond Belgium.