Temperature
Average dough temperature throughout bulk fermentation. The single most important variable.

Nine signals. One decision. Stop guessing whether your dough is ready.
Adjust the criteria below to see where your dough stands.
These shift the “ready” window for your specific dough. Set them once, then work the signals.
Average dough temperature throughout bulk fermentation. The single most important variable.
Hours since adding starter to flour and water. Time should be the last indicator you rely on.
Volume increase measured in a straight-walled container. The most reliable indicator of underproofing.
Is the dough surface domed with a visible "shoulder" around the edges of the bowl?
Large bubbles visible on the surface of the dough.
Bubbles visible through the side of a clear container. Shows internal fermentation activity.
Shake the bowl gently. How does the dough surface respond?
Stretch a small piece of dough thin. The earliest warning sign of overproofing.
Lift the lid and smell the dough. Your nose tells you what the clock can't.