Hi Joe,
Peaking of the starters is not given much importance in the bakery
I am currently connected. Just like with the bakers yeast raised
sponges in other part of the building of same establishment for their
normal doughs, they allow it to rise until it start to recede. And
when it does often times they just return the starter to the cold room
if they are stilll not producing any bread doughs at that time or there
was a change of worker shifts when it happened. or production was
postponed until several hours later.
Keep in mind that the * they are (using is pumpable )is fluid more
like of a waffle/pancake batter consistency.
Immediate refreshment when the starter starts to recede is done only
when there is large volume of that bread needed and they have to
maximize output by immediate refreshments so that they have enough
culture to use for the projected production output. for that period.
But its not the norm in that establishment to refresh the starter after
the peak period(10-12 hours. One old baker said its a waste of flour
and work time.; if the starter is still active why refresh it

Regarding the proper time to refresh...from what I saw
..I noticed that even if the starter is veiewed as riipe by its tendency
of receding from its maximum fermentation volume, the bakers just stir
the starter just to give it some sort of even dispersion of the
nutrients to give it some sort of slight aeration. It seems to
envigorate the critters. signficantly.Baking performance comparison
between the unstirred and the stirred starter seems to favor the latter
due to faster proofing time and the loaves are bold appearing( better
bread symmetry) and slightly better volume.
They have a also a machine that do the same thing every 8-12 hours in
the mechanized version of the process (has its own cooling jacket to
control the starter temperature)which they use in the peak periods of
the year..
Yes the starter do not rise to the same height but just bubbles and
form fine froths on the surface but is very active and can be used
for doughmaking with good results. The bakers do not refresh the
starter in the supposed expected basis such as starting at 8 hours-12
hours of fermentation, rather they just stir it and place the starter
bins in the cold room until used( about 12 hours .later).Therefore its
obvious that the refreshment time is only once daily.Or once every 24
hours.
Take note that this particular bakery do not add yeast in their
sourdough breads but use 100% really robust and vigorous levain. The
bulk dough fermentation at ambient is 2-4 hours and the proofing time
is at most 3-4 hours depending on the ratio of sourdough culture and
flour in the dough side preparation.
Although not all bakeries follow the same tecnique ,others still do the
8-12 hours refreshings in other bakery shops,, but presumably they are
using a different strain of sourdough culture.
In the same vein your starter is not the same as what others are using
so I cannot make a qualified statement that what is valid in the bakery
situation is identically suitable with your culture( or others) but
there is no harm in trying the technique<g>

Roy