The last few loaves I've baked haven't been my best so I'm researching the errors of my methods. One thing I've learned is that the Bulk Fermentation process doesn't end when dough is put in the refrigerator. I've read recently that some recipes call for 30%, 50%, 75% or 100% rise. The recipe I've been using since I started baking sourdough several years ago calls for "doubling" the size of the dough. My question is...how does one calculate the rise percentage during the bulk fermentation stage? Is there a way to accurately measure the rise or is it a guess-timate? Thanks for your help!
The "rise" is done by a guestimate. Feel free to measure it. Enjoy!
One thing to consider in the question is your bulk fermentation temperature...
As you note, fermentation continues while the dough is in the fridge, but slows significantly once the dough reaches fridge temp (39 degrees F). While the dough runs from room-temp to fridge temp, the fermentation continues. Just like a car traveling faster will take longer to stop, higher temperature dough will take more time to drop in temperature.
So (rough example) if you're fermenting at a room temp of 68F you could maybe get away with dough doubling, but at 78F you might want to shoot for a 50% rise. It also depends on your starter and flours.
I go by a rule of thumb that works pretty well for me: The dough will continue to ferment for about an hour after it goes into the refrigerator. So put it in an hour before you think it will be "ready".
The original question applies whether or not the dough is retarded - how can you tell if the dough has fermented "enough", however that is defined? One way is to ferment it in a container that has straight sides (and one that you can see the dough through the sides) so you can measure its height. The trouble is that most doughs will have a crown, making it hard to estimate the height accurately. The crown shape will probably be different later in fermentation, and that can make the measurement of height change even harder. Still, it's better than just using a big curved bowl.
Some bakers use an "aliquot jar" - search for it here on TFL - which is a tube of much smaller diameter than the fermenting vessel, normally marked with a scale on the side. At the start of bulk ferment you remove a sample of the dough and put it into the aliquot jar. The crown will be relatively smaller than in the bulk fermentation container so it's easier to make an accurate height measurement. However, differences in the dough processing such as stretch and folds can make the dough development in the aliquot jar different from in the bulk container. I haven't personally used an aliquot jar as yet so I can't tell you those practical tips that make it work well. I'm sure someone else will chime in here.
TomP
I find that it is nearly impossible to determine the percentage rise in a classic shaped bowl, Aliquot jar is better, though has the downsides Tom mentions. IMO, the best is a straight sided container, with a rubber band used to measure the height of the dough when you start BF. Cambro makes many sizes that are square. I just use round tuperware containers. The ideal size is one where doubling ( or whatever your goal is ) is near the top, so it is easy to see the progress. With straight sides, but an overly wide container, it is tougher to judge.