. . . .this video . . .
well, that really nothing different than saving a chunk of starter from one week to the next - as bakers have been doing for literally centuries.
once you have a starter going, and using it regularly, there is no need for the 'add&discard' bashed in the video.
you can make your own starter - it takes about ten days, and 'from scratch' does 'require' the add&discard routine to build up the yeast colony in the starter.
the issue whot occurs to me: how many people are baking a sourdough loaf every week?
I see posts where people produce stunningly beautiful loaves - 3,4,5,,,, we can't eat that much bread in a week . . . it's a reality issue....
one can buy a sourdough starter packet/powder . . . well, thinking that will continue to produce 'genuine SF sourdough' is not exactly correct. for many years the theory was 'wild yeasts' drifting through the atmosphere and into your kitchen were responsible for "flavor drift." now that the DNA types have joined the fray, seems yeasts in/on the flour itself are responsible.
another batch of scientists recovered - and propagated - yeast from multi-thousand year old Egyptian tombs, then brewed "the real beer of the Pharaohs . . ." - and promptly pronounced it 'terrible beer'
so, , , , yeast is really sturdy stuff, which put me onto the idea of freezing a starter for multi-week/month later use. . . . like - make your starter, keep it in the freezer for (pre-planning req'd) - dang good sourdough 'as needed'
put some saved bits of the last loaves in the freezer for next 'as needed' . . .