1. Day 1: The Beginning: In a clean, clear glass jar or container (at least 1-quart capacity), combine 1/2 cup (120g) whole wheat flour and 1/2 cup (120g) filtered water. Stir thoroughly with a spoon or spatula until no dry flour remains and the mixture is smooth. The consistency should be like a thick pancake batter. Cover the jar loosely with a lid, plastic wrap, or a clean kitchen towel (allowing air to circulate is important). Place the jar in a warm spot in your kitchen, ideally between 70-75 F (21-24 C).

2. Day 2: First Observations: On day 2, you might not see much activity, or you might notice a few small bubbles. The mixture may look unchanged or slightly thicker. Do not feed it today. Simply stir it once or twice throughout the day and return it to its warm spot. This resting period allows the initial microbes to begin their work.

3. Day 3: The First Feed: By day 3, you should start to see more noticeable bubbles, and the mixture might have a slightly sour or yeasty smell. This is a good sign! Discard half of the starter (about 1/2 cup or 120g). To the remaining starter, add 1/2 cup (120g) unbleached all-purpose flour and 1/2 cup (120g) filtered water. Stir well until combined. Cover loosely and return to its warm spot.

4. Day 4-6: Consistent Feeding and Activity: Continue the daily feeding routine: 1. Discard half of the starter. 2. Add 1/2 cup (120g) unbleached all-purpose flour. 3. Add 1/2 cup (120g) filtered water. 4. Stir well, cover loosely, and return to a warm spot. During these days, you should observe increasing activity. The starter should become consistently bubbly, rising significantly after feeding and then falling back down. You might see distinct layers of liquid (hooch) on top, which is normal and indicates your starter is hungry. Simply stir it back in before discarding and feeding. The smell should evolve from mildly yeasty to a pleasant, tangy aroma.

5. Day 7-14: Reaching Peak Activity and Readiness: By day 7, your starter should be consistently doubling or even tripling in size within 4-8 hours after feeding. It should be full of bubbles, both on the surface and throughout the mixture. When it’s at its peak, it will float if you drop a small spoonful into a glass of water. This “float test” is a good indicator that your starter is strong enough to leaven bread. Continue daily feedings until you consistently see this robust activity. Once it reliably passes the float test, your sourdough starter is ready to use for baking!