It’s almost incredible that such simple processes as creating a sourdough starter and using it to make bread should be the focus of so much misinformation. Loony instructions, such as leaving the flour exposed to outside air so it can gather wild yeasts (and a whole lot more, I’m afraid), using yeast to get a starter going (then it’s a sponge or poolish, not a sourdough), and adding vinegar to a dough to emphasise the sour flavour (save it for a salad) will all get results, but not necessarily a true sourdough starter or bread.