Controlling the sour in sourdough
When I make sourdough I typically use a formula from Bread by J. Hamelman. Ones that I have made include Vermont Sourdough (rye and wheat), Whole Wheat Levain, 40% Caraway Rye, Sourdough Rye with Raisins and Walnuts and others. I've also made the Sweet Potato Levain from Sourdough by Sara Owens. In addition, I have converted some of my yeast bread formulas to sourdough.
I mention this not to boast but to show that I have been trying to resolve the issue on my own. My latest attempt was to make the dough for two loaves of Whole Wheat Levain which is 50% whole wheat (fresh milled). Once the dough was shaped and placed into bannetons, one went into the fridge overnight and the other was baked after it had risen. Both loaves look alike and taste alike. I expected the later one to have at least a bit of a tang.
I have two starters at 100% hydration. One is given KAF AP flour and the other is fed fresh milled whole rye. Both rise the bread they are used in but neither is sour. They are each a few years old.
Usually, I do not want a sour flavor so all is well. But sometimes I am asked for 'sour' sourdough and I'm at a loss. I'd really like to have control over this.