Accelerated bulk rise and over-proofed loaves
I have been getting loaves that are over-proofed and flat.
I am using the standard Tartine country loaf recipe. I follow the method carefully and had mostly successful loaves in the past.
Recently, it appears that the dough rises super fast. Using 20% preferment, from autolyze to bulk, it took about 3.5 hours, and it was overdone. As soon as I made the turns it was obviously proofed and I had to bench, basket, and get them in the oven quickly, only to have them come out flat.
The next time I reduced the preferment by half (10%), and it was over-proofed in 4.5 hours.
I have been using the same starter I have had for years, recently feeding daily. I use the same ratio of bread flour, wheat flour, and water as described in the recipe for the loaves. The preferment is mixed the night before and is sufficiently doubled when I am ready to mix. The ambient temp during rising is between 78 - 80 degrees.
Considering I have always had success with the same recipe and circumstances in the past, I can only conclude that it may could be an over-active starter.
Otherwise, I can't explain why the rapid-rise and over proofing is happening.
If anyone has any insight I would greatly appreciate it.