The time required for the bulk fermentation can vary a lot. Mine took 3 hours. Don’t focus on time, but observe how the dough looks instead. It should have risen 40-50 % and show some bubbles on the top. The best temperature for bulk fermentation is about 77ºF/25ºC. If you have trouble finding a sufficiently warm place, you can place the dough into the oven with just the lamp lit.