Monday Morning's Miche from Advanced Bread and Pastry

Hello, This is my first attempt at making a miche, substituting a 13% spring wheat bread flour and a 75%-sifted Red Fife whole-wheat flour for the high-extraction flour called for in the formula.

Here is the result (springy! wasn't expecting that):


 mmm mmm good - we love the flavor!

Franko kindly sent me this link, which explained how to approximate high-extraction flour (thank you Franko!):
http://hamelmanchallenge.blogspot.com/2010/06/tech-note-high-extraction-flour.html
The calculation in the above link returned a 53% bread/47% whole-wheat substitution for the high-extraction flour.
This is factored into the baker's percentages I used, with the baker's percentages per the original formula listed below for comparison, in this table:

From SUAS. Advanced Bread and Pastry, 1E. © 2009 Delmar Learning, a part of Cengage Learning, Inc. Reproduced by permission. www.cengage.com/permissions

The first levain fermented for 16 hours, and the final levain for 7 (instead of the recommended 8 hours), but the final levain was starting to recede at 7 hours so I proceeded with the mix. I dissolved coarse gray Brittany salt in some of the water and added at the beginning of the mix and did not let the dough autolyse.

*Added to original post: The first levain and final levain didn't double during fermentation - perhaps only a 75% rise;
I am assuming because these levains are both salted and the salt slowed them down. I am used to seeing my starter/levains doubling after feeding/refreshing.
I was worried that maybe my levain for this bread might not be active enough so I threw in 3g of diastatic malt at the last minute when mixing, hoping this would help the dough through its long process. I'm not sure how much of an impact this may have had on the outcome.*

This dough was only supposed to bulk ferment for 15 minutes - there is a high percentage of preferment - I was curious about trying this formula as it's different from others I've tried. 
After the mix, my dough was a bit cool (72F instead of 75F to 78F as recommended) so I let it bulk ferment for a bit longer, a little longer than half an hour. Preshaped, rested boule 20 minutes, shaped and retarded in fridge for 12 hours.
I proofed the boule at 80F for one hour and 15 minutes prior to baking. The oven was preheated to 500F, reduced to 460F after loading and steaming, then reduced to 440F after 10 minutes. Total bake time was 38 minutes; left boule in oven with door ajar for 10 minutes.

This is a tasty miche and I'm glad to have tried it.
Happy baking everyone! from breadsong