Spontaneous fermentation and yeast water

Experimenting with yeast water. A marriage of my passions....wildcrafting, fermenting and ? .direct mix. 80% hydration with wild elderberry fermented water biga. 

6 hour bulk,  4 stretch and folds, 6 hour proof  

I also made focaccia with the same technique. I discovered this method in a book by the brilliant Italian bakers Carlo di Cristo, Ezio Marinato, Cristian Zaghini and Pierluigi Sapiente

"Le Fermentazioni Spontanee nei prodotti da forno"

There is also a facebook group all about fermented waters, but I am not on facebook.