reserve a piece of dough as a starter
I have searched in vain here and elsewhere for a no-recipe sourdough tutorial (not just someone having a go for the first time) that recognises that for 1000s of years people made sourdough bread without scales and measures, bowls and jars, or even recipes. They didn't keep a 'wet starter either' or waste precious flour by 'purging' the starter. They just kept a small piece of the dough from today's bread, maybe wrapped in a cloth, and worked it into tomorrow's dough. They didn't talk about hydration percentages, or about autolysing, but rather they passed down the know-how on how sticky the dough should 'feel', what it looks like when it has been kneaded enough, and how to know when it is ready to bake.
Can anyone direct me to videos that explain these things without recipes?