Weigh 4 oz of your unfed starter into a clean container. Discard the extra starter (see note)

Add the flour and water and mix until combined. Set aside at room temperature.

The starter is ready to use when it has doubled in volume and a small spoonful floats when dropped into a bowl of water. This generally takes 4-5 hours but the time can vary based on dough temperature and room temperature.

If you do not plan to bake with the starter on the day it is fed, refrigerate 3-4 hours after feeding.

Feed refrigerated starter weekly. If you go longer than a week without feeding, you may want to give the starter two feedings before using.