Prep Time 18 hours hrs 25 minutes mins
Cook Time 40 minutes mins
Resting Time 1 hour hr
Total Time 20 hours hrs 5 minutes mins
For best results, use an active, bubbly starter that has recently peaked, as sluggish starter will extend fermentation times and reduce oven spring. Room temperature greatly affects bulk fermentation, so in cooler kitchens expect the dough to take longer to double and look for visual cues—bubbles, domed top, and a lighter feel—rather than watching the clock. If the dough feels very sticky, lightly wet your hands instead of adding extra flour, which can make the loaf dense. Cold-proofing in the refrigerator not only makes the dough easier to score but also develops deeper flavor, so use it whenever your schedule allows. Finally, always let the loaf cool fully before cutting to prevent a gummy crumb and to allow the rosemary aroma and flavor to fully settle.