4 hours with 25% seems reasonable in a warm environment.
For estimating bulk proof time of a wheat dough, at room temp, in hours, as a rule of thumb divide total flour amount by starter amount. So with 100% flour and for example 30% starter, it should roughly take about 3-3,5 hours.
Of course this changes with hydration, temperature, when using whole wheat or rye, dough mass etc. But it's enough for estimating and it's fairly accurate for "standard" sourdough breads (15-40% starter, 70-80% hydration).
are you following an established/published formula (recipe), such as one of the major cookbook authors, or are you inventing your own formula?
4 hours with 25% seems reasonable in a warm environment.
For estimating bulk proof time of a wheat dough, at room temp, in hours, as a rule of thumb divide total flour amount by starter amount. So with 100% flour and for example 30% starter, it should roughly take about 3-3,5 hours.
Of course this changes with hydration, temperature, when using whole wheat or rye, dough mass etc. But it's enough for estimating and it's fairly accurate for "standard" sourdough breads (15-40% starter, 70-80% hydration).