Sourdough Boule - again

This time, I'm sticking to the recipe. Can you believe it? I'm actually sticking to a recipe. Anyway, this time the fraction of starter is lower and I'll be using wheat germ in the recipe.

Prep
1. Silverton's white starter (fed only 4 hours ago, 200 g), water (300 g), unbleached white flour (500 g), salt (10 g, kosher) and wheat germ (1/4 C).
2. No autolyse, just machine kneaded for 13 minutes.
3. Let ferment @ 64F for 3.5 hours (while we went shopping and to the feeding troughs of Hometown Buffet).
4. Punched and let rest for 30 minutes at 74F.
5. Shaped into a boule and placed in my linen-lined proofing basket covered with plastic wrap (my banetton) and placed the covered basket in the fridge (8 pm 7/10/04 -> 8 am 7/11/04), internal 49F (I think this 49F is an error, the internal temp of the fridge I used was 42F and I think I didn't get the probe in the right portion of the dough and for some reason got an inaccurately high reading).
6. Warmed for an hour and returned to the fridge for an additional 6 hours (49F, registered "internal") while we spent a day caving and removed it again for a 1.5 hour warming; I got impatient. Internal read 52F before baking, should've waited).
7. When internal reached 52F, docked, put in oven on clay tiles @450F with steam shot.
8. Baked about 35 minutes. Final weight 872 g.

Results
I think I jumped the gun on the baking (I really wanted it for dinner) and baked it about 10 minutes too short. The innermost part of the crumb looked a bit undercooked. Either I baked it with too low an internal temp and/or baked it too short. The exterior was killer though. Deadly crunchy crust (Frankie nibbled on the heel).

P.S.:
By the way, I realize some may be bored by these repeated sourdough loaves, but this blog is essentially my kitchen lab notebook. So, often, these entries are for me more than anyone. Some of you more tedious bakers might appreciate the entries. Also, I'm building to a spectacular multi-grain loaf. I had it in Strasbourg a few years ago and I'm trying to achieve a similar loaf through these trials.