A Tale of Vanishing Sourness,
or Too Many Changes Addle the Brain
Recently, I made some sourdough levained baguettes, Sourdough in Baguette's clothing  and was delighted to find their flavor included a distinct acidic tang (sourness) that I especially like, but my wife usually doesn't. However, with this bake, I caught her returning more than once for another slice of the cut loaf. When I confronted her, she allowed the flavor was "interesting"--and took another bite.
The baguette dough was similar to the dough I bake weekly in batards: our daily bread. The differences are:
Original Formula Baguette Formula
Flour ratio: 45%AP/45%Bread/10%Whole Rye 66%AP/24%Bread/10%Whole Rye
Preferment: 28% (100% Hyd., all Bread Flour) 49% (100% Hyd., all Bread Flour)
Additionally, I routinely build levain from refrigerated seed starter in three progressive steps, feeding 2:1:1 at eight hour intervals. For the baguettes I allowed the third feeding to ferment for 12 hours.
Salt and Hydration was the same for both: 2% and 68% percent respectively, and, except for the loaves' final shape, all the dough handling, fermentation times, fermentation temperatures, and baking temperatures were the same. Batards are generally proofed at 82°F, baguettes at 76°F (RT) because they won't fit into my proofing box.
Over the last two days I built levain, made dough and shaped three batards. The intention was to duplicate the dough I used to make the sourdough baguettes, and experience the same flavor.
However, I have a very strong Imp of the Perverse in my flawed character. I couldn't resist making more changes. Specifically, I built the levain in three progressive stages reducing the hydration of each build by one-third the difference between the seed starter hydration (100%) and the final dough hydration (68%). I let the final build, at 68% Hyd., ferment for 12 hours. Seduced by the sourdough lore that stiffer levain favors bacterial acid production, I reasoned "Hey, it can't hurt!".
Furthermore, I returned to the original flour ratio 45%AP/45%Bread/10% Whole Rye. And, to exacerbate my sins, I put three teaspoons of diastatic malt powder in the final dough. I wanted a darker crust.
I cannot detect any flavor difference in the finished loaves compared to our weekly sourdough bake. The distinct tang has vanished. Of course, with all the changes I've nary a clue why.
But I did get a darker crust.