Proofing Dough
For some time during my early bread baking, I would periodically have a dough ball that would partially collapse when I went to slash it prior to baking. As it turns out, this is a classic example of over-proofing the dough. In general, over-proofing is when the fermentation process has strained the gluten to its limit and the gas buildup in the dough has stretched gluten to its breaking point. At that point, any slight disturbance will cause a collapse of the dough.
In addition to following fermentation timeframes described in proven formulas, always monitor the final proof stage to ensure that you haven't reached the over-proofing stage. A good way to do this is to dip your index finger in flour and then lightly poke the pad of that index finger into the dough and indent the dough about 1/2 inch. If the indentation rises back immediately, the dough is under-proofed. If it springs back somewhat, but still leaves an indentation, it's probably fully proofed. However, if the imprint remains without springing back, the dough is over-proofed. Avoid getting to this stage.
My general rule is that it is better to under-proof the dough than it is to over-proof the dough.
In addition to following fermentation timeframes described in proven formulas, always monitor the final proof stage to ensure that you haven't reached the over-proofing stage. A good way to do this is to dip your index finger in flour and then lightly poke the pad of that index finger into the dough and indent the dough about 1/2 inch. If the indentation rises back immediately, the dough is under-proofed. If it springs back somewhat, but still leaves an indentation, it's probably fully proofed. However, if the imprint remains without springing back, the dough is over-proofed. Avoid getting to this stage.
My general rule is that it is better to under-proof the dough than it is to over-proof the dough.