Soft Crust

The last sourdough bread I baked had a soft crust, but I'm not exactly sure why. In this case the outer surface of the dough was coated with olive oil before it went into the bowl to rise. Rarely do I place a dough in the refrigerator to retard its leavening properties, but this time I had no choice. Friends were visiting and we already had plenty of bread. I wanted to bake the next day, and that's what I did.
After preheating the oven, I took the bowl of dough from the refrigerator and flopped the cold dough directly on the quarry tiles. Then I covered the dough with my flower pot cover. The dough was much softer than usual when it went on the tiles. I baked it at 475 undercover for 15 minutes and then at 400 for 30 minutes.
The bread was excellent, but the crumb was quite uniform. Usually I get irregular mouse holes.
The reason for the soft crust probably had something to do with the olive oil and the long proof in the refrigerator. More experimenting is called for
Check out the photos.