On Mar 8, 7:42*pm, "Dick Adams" > wrote:
> "Doc" > wrote in ...
> > [ ... ]
> > If I want to increase the sourness further I retard the dough overnight at
> > about 55-60°F before baking and/or add/increase the amount of whole
> > grain flour in the mix.
>
Dick Adams said:
> So you must believe that cold incubation gives the souring bacteria
> the edge over the yeasties, who are simply blowing gas.
>
> I believe that the yeasties do their stuff and give way to the bacteria
> when their food is gone. *I even believe that the bacteria feast on
> the starving bacteria. *I believe that the sequence procedes slower
> in the cold.
>
> > it is not the pH, but the TTA that makes the loaf sour.
>
> Actually, I do not exactly know what sour is. *I guess it is safe to say
> that it is an opinion, a perception, a state of mind ...
>
> Hard to objectify when such a thing is a parameter.

Dick,
Always interested in your opinions.
They make me think.
I guess it is sort of Darwin in a dish, but I too don't know exactly
what is going on.
Certainly competition, but under some conditions synergy.
My starter today is probably not the same as when I originally got it,
but it seems stable and works for me.
There may an advantage for the LAB at low temp and you can find a temp
below which there is little observable yeast activity
But I am not convinced that the yeast has actually shut down.
The lower temperature definitely increases the solubility of CO2 so
that instead of "blowing gas" into bubbles, the gas is just absorbed
by the liquid.
There is some CO2 diffusion through the medium and probably some loss
at the surface.
Hard to say what the balance is.
At least one paper I found on multivariate sensitivities provided
interesting but not very useful curves on mutual dependencies.
So the science and the art go forward hand in hand.
I am still looking for the definitive experiment to prove that the
blisters on the surface of a retarded loaf are CO2.
Doc