This is a picture of some really big ( for me at least) 5  pound miches that I baked for my Boy Scout troop's dinner, these were 10%
whole wheat, 90% bread flour,made with 'Mikey's NJ' starter, and a big hit at the dinner.

Not the best photography, but you can see how pretty these were

I like using part whole wheat ( or rye) in my sourdough, it makes a bread that is definitely not made with plain white flour, but it is white enough  to use as an everyday bread, rather than being a whole grain type of specialty bread. I have been making these loaves with both my own starter  and with one from Carl's friends, both work well, the 'Carl's Oregon Trail'  starter rises a little faster and makes a less sour bread with a rather pale  but tasty crust, the 'Mikey's NJ ' starter rises slower but makes a more  sour loaf, with a richer golden brown crust that I love.

My procedure is to refresh the culture the day before, then after 14 hours  make the dough. About a 4 or 5 hour bulk fermentation with 2 foldings during  it, then the boules are shaped, risen for an hour, and then retarded  overnight. The next morning I take them out of the fridge ( or garage..in  the winter I retard there), give them 3 or 4 hours to warm up and finish  proofing, then into the oven at 550 with steam, reduced to 450 after 5 minutes. These big ones I baked for an hour, then lowered the heat since they were getting dark, and left them at 400F for another 20 minutes to make sure they were done. Internal temp was 205 when I took them out of the oven, the crust was crackly and delicious and actually stayed that way, instead of softening as it cooled. I guess that extra baking time helped.

 Mikey in New Jersey