Caffe Sociale bread in San Francisco

I recently visited this fine establishment and tried their complementary bread. Has anyone who has tried the bread know how they're getting that flavor? It's quite honestly the most flavorful bread I've ever had. It tastes like.....bread (no herbs, garlic, cheese etc), I don't know any other way to describe it. The baguette's insides are soft and pale white so I'm going to assume they're using fats/eggs, but it's not the texture that I want it's the flavor of the bread that I'm after. 

I've only been baking for about half a year or so (Chad Robertson's Tartine bread, Peter Reinhart BBA recipes etc) so I'm not too experienced in this extraordinary field of cooking. I have only experimented with AP flour, bread flour, and whole wheat flour. Is the flavor that is given from an extra long fermentation or a specific type of flour? If anyone has been to Sociale and knows, any help would be greatly appreciated. Thank You! 

Sociale

3665 Sacramento St

San Francisco, CA 94118