Gauging Growth Stage
I've been reading and thinking about sourdough growth. Most instructions refer either to time or to the activity of the start. It is asserted in at least a few places that different starts may be "faster" than others though I have a hard time believing tha if one is to believe that the dominant species in those starts are L. sf and C. milleri.
It seems to be a common belief that when the start or dough has risen as high as it goes and stops rising, that the start activity has peaked. In other words, that it enters the transition to the static phase. But I wonder if this isn't an erroneous assumption. Dough, and especially the more fluid starts, are hardly airtight. I think the only thing that can be said is that an equilibrium has been reached where gas production is at least high enough to counter gravity to the extent that the gluten structure will allow it to rise.
It seems like this may even be true even early or midway through the exponential phase, or well into the death phase. Or maybe not—I'm not sure and this is my question. Does anyone know of a good way (without scientific instruments) to estimate the growth phase of sourdough? Particularly, the transition to static phase, but any indication that it's in static phase would be useful.