[malfist]

Starters are a mix of bacteria that produce either lactic acid or acetic acid. If yours is never turning out sour enough you might be: using too much commercial yeast, not using enough starter, or having a starter culture biased towards lactic acid.

The first two are easy to fix. The third one is saying you need to keep your starter culture a little bit cooler. I keep my downstairs where the starter is between 62-67 during the winter and its plenty sour. I think dryer starters might be less sour, but I'm not sure. I run mine 100% hydration.

I'm currently baking this recipe: 300g bread flour, 300g whole wheat flour, 227g starter (100%), 541g water, 18g salt, 1/8tsp of commercial yeast. All the usual baking steps, over night retard. Two loaves