Mix together ½ cup of flour with ¼ cup of water in your jar. Stir until well combined, aiming for a pancake batter-like consistency. Let it rest for 30 minutes to kickstart the fermentation process.

Stir the mixture thoroughly, then cover it loosely with a paper towel secured by a rubber band. Let it sit at room temperature for 24 hours, allowing the natural yeast to come alive.

Check for tiny bubbles indicating activity. If you see them, great! If not, give it a little stir and wait one more day for nature to work.

Remove half of your starter and discard it. Add another ½ cup of flour and ¼ to ⅓ cup of water to the remaining mixture. Stir well, then cover and let it sit for another 24 hours.

Repeat the process again—remove half, feed with flour and water, and let your starter rest for 24 hours.

Days 4 through 6 are pivotal; you can feed your starter twice a day if you like until it doubles in size within 8 hours.

Once your sourdough starter is thriving (usually after about a week), you can store it in the refrigerator. Remember to feed it weekly.