A sourdough alchemist respects their materials. You cannot transmute base metals into gold if your base metals are corrupted.
1. Earth (Flour)
Flour is food for your microbes and structure for your loaf.
Protein is Structure: You want bread flour. It has higher protein content, which forms stronger gluten strands to trap the gas.
All-purpose flour can work, but may yield a flatter loaf. Whole Grains are Nutrients: Whole wheat or rye flours are packed with minerals and natural yeasts. Microbes love rye.
Adding a little rye to your starter feeding acts like steroids for fermentation.
2. Water
Water is the medium in which life occurs.
Chlorine is the Enemy: Tap water often contains chlorine or chloramine, designed to kill microbes.
It will hinder your starter. Use filtered water or let tap water sit out uncovered for 24 hours so the chlorine evaporates. Temperature is the Accelerator: Dough is alive.
Warm water speeds up fermentation; cold water slows it down. You control the pace with temperature.
3. Salt
Salt is not just for flavor; it is the regulator.
The Inhibitor: Salt slows down fermentation.
Without it, the yeast would go wild, eat all the sugar too fast, and the dough would collapse. The Strengthener: Salt tightens the gluten structure, making the dough less sticky and easier to handle.