Very Tight Dough using Straight Starter
I've been experimenting for about 2 months now with different forms of sourdough for my pizza and I just can't seem to get it right. Recently, I tried a suggestion of completely ditching the leaven and using a small percentage of my active/ripe starter as I would yeast. The aroma and flavor have been promising, but my dough balls are feeling very tight and I'm wondering if anyone knows why this might be. It's happened with King Arthur (malted) bread flour and Caputo 00 (unmalted) flour.
Flour (100%,) Water (63%,) Salt (2.8%,) Active Starter (1.5% - 100% hydration, 100% whole wheat-fed.)
Workflow: Dissolve salt into 50f - 55f water. Add starter and dissolve; froth up. Add flour. Mix until shaggy, autolyse, hand-knead until pretty smooth. Rest again, another few kneads. Into container to bulk ferment at ambient room temp (mid 60s) for 24 hours. See little activity in the bulk - some bubbles and slight volume increase. Ball next day (after the 24h bulk.) Balls feel smooth and look like they seal well. Proof in balls until 90% proofed and ambient room temp (takes about 12 hours or so.) Store in cooler until ready to bake; pull and temper at room temp until ready.
My bulk dough smells very well fermented (but not in a bad kind of sour way.) I'm noticing when I go to bake, when I pull the balls out of the tray what I thought was a well sealed bottom has almost kind of separated from the ball. That is, it's not a smooth, sealed surface. You can actually see where it was pinched shut. When beginning to press out, you can feel it's very elastic and somewhat tough to open. I get about 50% of the way there, then pick it up to toss it, and you can almost see thin spots where it's on the edge of tearing. Sometimes I will get a tiny hole. Other times, it doesn't tear but it's very close.
Does anyone know what might be causing this?
My guess was the long bulk I'm using to develop flavor is strengthening the dough too much, as it's happened with both varieties of flour.
Any suggestions or thoughts welcome...