How is Panera's Sourdough bread supposed to taste?

[Monstera deliciosa]

Does anybody know what Panera's Sourdough Bread is supposed to taste like? Very sour? Slightly sour? Somewhere in between?

Over a year ago, my husband brought home some small round loaves of sourdough bread to use as soup bowls. You know the deal: Cut off the top, scoop out the innards, fill with soup. At the time, the sourness of the bread permeated the soup unpleasantly, and I found that the bread innards were too sour to enjoy eating as an accompaniement. Ugh! Yuck! Ptui!

Well yesterday, we decided to do the bread bowl thing again. I had assumed (yeah, I know) that since I hated the sourdough last time, my darling would bring home something else.

Well, as I was heating the soup, I picked up some of the bread innards and started noshing. It was yummy, but had just the barest perceptible hint of sourness, so I asked my husband if he had bought sourdough again. The answer was "Yes." But the difference in the flavor of the bread was like night and day. It was pleasurable to consume on its own, and the soup didn't get sour either.

If we are going to do this again, I need to know which one was the fluke. Or does the process of fermenting the dough make the sourness too variable to predict?