SOUR sourdough

My first post, so please be gentle.

I grew up on the central coast of California, where I took for granted the unique flavor of certain sourdough breads.  Anyone from that area knows what I mean if I refer to either Boudin's (SF) or San Luis Sourdough products.  In essence, it's a very tangy sour dough flavor, and the bread is spongy in texture.  Having lived in the Denver area long enough to forget this tangy effervescence, I recently visited the Bay Area and was reminded of this particular taste while dining in Fisherman"s Grotto on the warf.  I know of no bread companies in Colorado that have this particular nature.  Since returning home, I've spent dozens of hours surfing the web for all knowledge on sourdough baking, and as many hours experimenting with different recipes..

I've purchased and started a San Francisco Sourdough Starter from a vendor on Amazon.com, (which didn't go as well as I had wished), additionally I've succeeded in starting a native culture with just water and four (which is my most active, by far!). 

I'm using unbleached unbromated flour and spring water from the market.  I add starter, flour, salt and water to a food processor and when it becomes a nice rolling ball I take it out and knead it on the counter with flour.  I've followed some recipes that call for 2 1/2 cups of flour and 3/4 cups of starter.  I've done my own creations with a quart of starter and enough flour to make a nice dough ball on the baking stone. 

Method One:  Put the dough ball into a slightly oiled zip lock bag, then refrigerate (41F) for 24 hours.  It's got visible holes in the dough surface, but hasn't risen noticably.  I leave it on the baking stone for approx 12 more hours, when it's doubled in size, then bake (liberal usage of water spray bottle).

Method Two:  I put the dough ball on the baking stone, allow it to double in size, 12 hours, then bake.

Method One has produced some very flat, dense loaves, Method Two has been the best texture (ie. a french loaf).  I get the most sour flavor in Method One, but who wants to eat a flour brick?  I still haven't been able to acheive that tart, biting flavor I'm trying to acheive. 

I understand the symbiotic biochemical relationships between the yeast and bacteria (being of a medical background), and how this effects the pH (I'm guessing I want a low pH?), and I've recorded the times and temperatures of loaves I've experimented with so far.  I've yet to discover the secret of extra sour dough flavor.  I'm now to a point where I'm adding superfluous ingredients to my doughs...diastic malt, 2% milk, sugar, bread yeast...and still nothing but the usual, bland, SEMI sour dough flavored bread sticks. 

I've joinded this forum to answer one primordial question:

          "How do I make a tart, tangy, extra-sourdough flavored bread?"

(Without having to age my started 150 years!)

Thanks for any  helpful advise,

GreenSpyder