In a quart-sized jar, add 1 cup of whole wheat flour. This will be the base of your starter, providing the necessary nutrients for yeast growth.
Add 1 cup of warm water to the flour in the jar. Make sure the water is warm but not hot, as too much heat can kill the yeast.
Mix the flour and water together until you have a smooth paste. This should not be too thick or too runny; aim for a pancake batter consistency.
Screw the lid tightly on the jar and set it aside on your kitchen counter for 24 to 48 hours. During this time, the mixture will begin to ferment and develop bubbles.
After about 24 hours, check for bubbling activity. If you see small bubbles forming, that means your starter is on the right track! If it hasn’t bubbled yet, give it more time.
Once bubbling is observed, it’s time to feed your starter. Discard all but half a cup of the starter mixture from the jar.
Add in ½ cup of whole wheat flour and ½ cup of warm water to the remaining starter. Mix well until smooth.
Screw the lid back on and set the jar aside again for another 24 hours. Repeat this feeding process once a day.
If your starter is bubbling up more quickly, consider feeding it twice a day instead of once.
Continue this process for six days. On the sixth day, when your starter is active and bubbly, you can use it in your sourdough bread. Instead of discarding half, simply remove half and set it aside for your baking.