At the Sourdough Library, With Some Very Old Mothers
Some starters never die, they just get filed away here.
the Puratos Center for Bread Flavor, the world’s most extensive collection of sourdough starters, in St. Vith, Belgium
https://www.nytimes.com/2020/04/11/science/sourdough-bread-starter-library.html?
Thanks for the link. That's a good story.
Ed Wood's Sourdoughs International, on a much smaller basis, and commercially, does something similar.
https://sourdo.com/all-products/
16 strains. Several out of stock at the moment.
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For my last two starters, I've fed them with only white/refined flour (AP or bread flour) in order to lessen the chance of introducing outside yeasts/lab. The last one I purchased from Cultures For Health seems to have maintained its flavor and not evolved.