I have often wondered why doughs placed in fridges for either bulk fermentation, or proofing, continue to ferment in the fridge. After all the yeast activity slows with decreasing temperature and at 10C / 50F its activity rate is just 1% of it's peak activity at approximately 26C - 29C, 79F - 84F.
Today I came across a graph where someone had made continuous measurements of the dough temperature, using a remote temperature probe, of their 1.5kg of dough cooling in their fridge. The dough was in two pieces in proofing baskets. And there was nothing else in the fridge. The fridge was a domestic one and it chilled the dough down to 4C, 39F
These were the results:
24C 75F Initial dough temperature
20C 68F The dough is fermenting at 50% of its maximum rate. It took 1 hour to fall this far.
15C 41F The dough is fermenting at 25% of it's maximum rate. It took 2h 45minutes to fall this far.
10C 50F The dough is fermenting at approximately 1% of its maximum rate. It took 4 hours to fall this far.
5C 41F The dough is fermenting at pretty much 0% of it's maximum rate. It took 7 hours to fall this far.
Of course if the dough is placed in the fridge at a temperature higher than this test's 24C the chill times will be longer.
At 10C 50F and below for all intents and purposes we can regard fermentation as being halted. Though enzyme activity degrading the gluten will continue all be it at a slower rate.
For this reason cold fermenting is an art. We each need to learn from experience when to put a dough into the fridge allowing for this continued fermentation. I tend to give my dough 15 minutes on the work top before putting it in the fridge to proof for 12- 16 hours. Some people put the proofing basket, or tin, straight into the fridge afer shaping. Your fridge will likely be different.