Making Bread More Sour

I have had some luck using small amounts of starter ( 5 %) and long ferment times at cool temps  ( 64 F ), and have also done well using small amounts of starter and doing final proof at high temps  ( 95 F )  though you really have to watch it to avoid overproofing.   

I would like to ask the same question but in the other direction.  How to make my "sourdough" - much much less sour.  I don't like sour so what do I change to make much less sour or even "sweet".  I not trying to hijack this subject just wanting to understand what move this in both directions.

One of the more useful methods in the search for the perfect sourdough is the age old French "travail sur trois levains", or three-leaven work. Begin by searching on "travail sur trois levains". The second stage ferment can be stretched in time to control the "sourness" of the final bread.

The only problem you'll end up with is how to adapt your other natural bread recipes to this method...,

Wild-Yeast

Deblacksmith,  in general, you want a shorter fermentation time so that it will be less sour.  So while I suggested that logan use 5% starter, you might want to start at 25% .  Yes, the more sourdough starter you add, the less sour the end result.  This is a great link on the factors that impact sour.  http://brodandtaylor.com/make-sourdough-more-sour/