Most new sourdough bakers do the same thing after a dense, gummy, or underbaked loaf: they buy a different bag of flour.

It feels like progress. It is usually a reset.

If you change flour, hydration, starter timing, and oven setup in the same week, you cannot tell which one moved the crumb. You get another mystery loaf, then another bag.

Keep one flour. Write the bake down.

After a few logs you will see the same handful of causes:

• Starter was not strong enough when you mixed

• Bulk ferment was short for the room temperature

• Proof looked ready and was not

• Oven was not hot enough, or the loaf came out early

Airy, fully cooked bread is a pattern, not a shopping problem. Record flour brand, hydration, starter strength, timing, bake temperature, crust color, crumb openness, and doneness. Review those notes before you mix the next dough.

That is the whole system. Same ingredients. Better records. Better loaves.