After kneading, shape your loaf, cover it, and let it proof for 4-24 hours, depending on your specific sourdough starter and ambient temperature. You can manipulate the sourness of the bread with a longer rise time. A 24-hour rise time will produce much more sour bread than a 4-hour rise time.
As a very basic time frame, the very minimum that sourdough should ferment/proof for is 4 hours.
For example, in the summer the dough can take anywhere between 2-4 hours @ 85º F/ 29º C. In the winter, it will take longer about 10-12 hours @ 68º F/ 20º C. Temperature controls time. And remember: because sourdough bread does not contain instant yeast it will take longer to rise.
Under-proofed dough will spring back very quickly, and feel quite dense to the touch. This is because the yeast has not had enough time to produce enough CO2 gas to be trapped in the dough structure. Properly proofed bread will slowly spring back when touched, refilling the indent from your finger in about 10 seconds.
If you don't let dough rise long enough then the bread will be dense, rubbery, and less flavorful. As the yeast ferments, it fills the dough with gas and gives the bread its airy texture. The flavors also come as byproducts of fermentation.
A 24-hour rise time will produce much more sour bread than a 4-hour rise time. If using a shorter rise period, 4-12 hours, a second rise is optional. If desired, punch dough down, reshape, and proof a second time.
When your dough is over-fermented, the scores will not “open up” during baking but instead will flatten and melt into the dough. Scores don't really open up. The resulting bread will be flat and not have a good oven spring. The crumb can look dense and compressed, especially towards the bottom of the loaf.
To proof them, let them sit, covered, at room temperature for up to 3–4 hours, or let them proof for a little while at room temperature and then place in the refrigerator for 12–15 hours. Or you can speed the process by using a proof box, warm cooler, or slightly warm oven to speed things up.
If the dough has not risen in 10 hours, all is not lost! Sourdough rise time simply takes longer in cooler environments. Allow it a few more hours as the dough may simply be forming air bubbles more slowly. On the other hand, in environments above room temperature, the dough may rise faster.
Overproofed sourdough dough loses all structure, so it's stretchy and slack when turned onto a work surface. The dough is also stickier than usual due to the lack of remaining gluten structure.
Most commonly, the issue here has to do with temperature (which is very important). If your sourdough starter is kept at a low temp, even 70°F (21°C), it will slow fermentation activity and appear to be sluggish, taking longer to rise and progress through the typical signs of fermentation. The solution: keep it warm.
You really only need to handle sourdough minimally. Each set of stretch and folds should consist of 4 stretches and folds. You should aim to do around 4 to 6 sets, but you may need less depending on the dough strength.
Proofing (aka final fermentation, final rise, second rise, or blooming) is the dough's final rise that happens after shaping and just before baking. The entire dough fermentation process is sometimes referred to as the proofing process.
Covering the dough will create a warm moist atmosphere for the dough to rise nicely in. If it's cold or dry the dough won't rise as well as it should. So covering the dough while it rises keeps the moisture IN and the drying air out.
You most definitely can bulk ferment sourdough too long. If you leave the dough to ferment for too long, it will become "over fermented". Over fermented dough will lose its structure and become a soupy, sloppy mess that you will not be able to shape.
The second rise is shorter than the primary fermentation after the bread loaf has been shaped and panned; usually taking only about half the time of the first rise at room temperature, or shorter for smaller loaves and rolls.
You can chill your dough during either the first or second rise. Your yeast won't give you much love if it's asked to do both rises in the fridge, so it's best to do one or the other at room temperature. One of Clara's favorite recipes to make with a cold ferment is Vermont Sourdough.
Over-proofed Dough:
If the dough is only slightly over-proofed at the end of bulk fermentation, divide and shape the dough into a banneton immediately and place it directly in the refrigerator. The cold temperature will slow down fermentation and your bread will likely end up okay.
Your dough can become sticky when you add too much water or the flour isn't suitable for the type of dough you are making. Over proofing or fermenting the dough can also result in the gluten structure weakening causing sticky dough.
The dark liquid is a form of naturally occurring alcohol known as hooch, which indicates that your sourdough starter is hungry. Hooch is harmless but should be poured off and discarded prior to stirring and feeding your starter.
Absolutely you can overcook sourdough bread. Just like yeasted bread, sourdough bread can be left in the oven too long. Overcooked sourdough bread will have a very hard, crunchy crust that is difficult to cut and bit through. The interior of overcooked sourdough bread will be drier than it should be.
While this might not taste bad, it does move you further away from achieving the perfect sourdough bread. Open crumb, on the other hand, has a light, fluffy interior that is characterized by large, even holes/bubbles.