You are now the proud parent of a sourdough starter.
Mix together equal quantities of starter, unbleached flour, and filtered water. It is best to measure by weight for accuracy. The starter will grow significantly after feeding so make sure you have enough room in your jar and discard some starter if necessary. Pro Tip: Discarded starter goes great in crepe batter, pizza dough, and fresh tortillas.
The feeding frequency will depend on your needs. It is best to try to develop a regular feeding schedule, whether that is every 24, 12, 8, or even 6 hours. Observe it to see when it reaches its peak - that is when you should use it (roughly 3-6 hours after feeding). If you aren’t baking as frequently, place the starter in the fridge and feed once a week (allowing it time to rise at room temperature). To wake the starter up, simply take it out of the fridge and feed it.
Different flours will have different effects on your starter. This is a living organism and will behave differently depending on its environment and what you feed it. Use only unbleached flour. Organic flour is great because it often has more natural yeast. We also like to use a combination of whole wheat and white flour. Whole wheat flour will make your starter more active than white flour. Rye is also a popular choice and is used for sourdough rye breads.
Chemicals in tap water can kill the yeast in your starter. Make sure you use filtered water or, leave water out for 12 hours and then use, this removes the chlorine. When feeding, warm the water to about 100F/38C.