Mix 6 cups of all-purpose flour with 3 cups of whole wheat flour and store it in an air-tight container. This is what you will feed your starter with.

DAY 1: Add 1 cup of flour and ½ cup of water to a clean jar. (120g flour + 120g water) Stir the mixture thoroughly and cover the jar with a lid or breathable cloth, secured with a rubber band. Place the container in a warm location, around between 75°F (24°C) for 24 hours.

DAY 2: Give the starter a stir to help incorporate a little air. Cover the jar and let it rest for another 24 hours in a warm spot.

DAYS 3-7: Every 24 hours, discard all but 2 tablespoons of the starter and feed it with ½ cup fresh flour and ¼ cup water. (60g flour + 60g water) Mix thoroughly until well combined. Repeat this daily feeding routine, discarding and feeding, for about 7 to 10 days or until your starter becomes active, bubbly, and doubles in size within 4-12 hours of feeding.

If your starter seems sluggish after the 4th day, begin stirring in 2 tablespoons of flour along with 2 teaspoons of water into the starter, 12 hours after you fed it. This will help to give it a boost until the next feeding.

I recommend continuing to feed your starter daily for the first two weeks after you've gotten it established in order to keep building up the yeast and bacteria. This will provide you with a very robust and mature sourdough starter.

I have written an article that provides comprehensive guidelines and tips on maintaining a sourdough starter, covering aspects such as feeding schedules, temperature control, troubleshooting, and flavor development. It offers valuable insights and practical advice to help you keep your sourdough starter healthy and vibrant for successful baking adventures.