Can you tell me why you use a 5+20 fermentation method? Currently, I do the exact opposite: 20+4.
Dear Salvatore, when I employ sourdough culture as a fermentative agent, I often, not always, use the "5+20 fermentation" mode for a number of reasons. The principal reason is that it works, for me! It procures the soft, yet stable, texture and mild sourness I favor in a dough fermented with sourdough culture. If you ask "why", this is where I need to speculate, without hopefully falling into error, as to what causes those qualities.
Given the type of flour and the hydration level I use, five hours of bulk fermentation does not considerably breakdown the gluten bonds throughout the dough; consequently, it is more efficacious toward making dough balls of stronger, unbroken, and uninterrupted skin. Another reason pertains to the exponential growth
of the bacteria and fungi in dough. Since the fermentative micro-organisms within dough multiply exponentially, I assume that the sooner the dough mass is divided into dough balls, the slower will be the rate of fermentation, which in turn is productive of less lactic acid (sourness). Needless to mention, it is crucial to control the temperature throughout the process. Also, the "5+20 fermentation" mode reduces the annoying gummy residues, if any at all, on your fingers when making dough balls. (I do not know how cogent my preceding rationale, i.e., the exponential growth, is.)
At last, for me, the "5+20 fermentation", in contrast to "20+5 fermentation", produces dough balls that are more relaxed, softer, and easier to stretch into dough discs that bake into more tender crusts. Naturally, the "5+20 fermentation" mode requires use of minimal amount of yeast or sourdough culture. After all said and done, when it comes to making sourdough pizza dough, it is often recommended to follow "21+5 fermentation" or a variation thereof. Have a great day!