This question was sent to me via email:

I have been making bread since the mid 1970's. During the past few years, I have been experimenting with starters instead of using variations on the straight yeast dough method.

More recently, I have been experimenting with starters, sour dough, and
related approaches based on recipes and instructions from several of
Peter Reinhart’s books. The bread usually comes out fine although
the process is labor-intensive and time-consuming.

With all of the reciepes in several of his books, I seem to wind up
throwing away a lot of starter or seed. Starting with a small
beginning batch, I let it rise. After the indicated period of time, I
work on it for a few minutes. Instructions say to let a portion of the
starter rise again and suggest that I can discard the rest that is not
needed. Too much starter retards growth of the yeast and the ripening
of the dough.

Am I reading the instructions correctly--does the starter/sour dough
method always give the cook excess dough at the end of each step or
rise that must be thrown out?

Thanks to whoever can provide an answer or guidance?

FYI Reinhart was on one of the cooking shows on NPR. Either he or the
host offered an email for listeners with questions. I asked this same
question but did not get an answer.

I believe the answer is yes, you always end up needing to discard some extra starter.

The last story I can find on NPR.org that Peter was in was this story about pizza from November [1]. If anyone can find a more recent one, please post it.