Mixed Flour Levain with Long Autolyse
There has been lots of discussion here and elsewhere (notably Ken Forkish in FWSY and Ian in his Ars Pistorica blog) on the benefits of long autolyse. I thought I would do a side by side comparison to see what the difference in taste is, since, after all, that's the main reason we all bake so much. Just for fun, I also wanted to try a more complex levain. I have been using a simple straight wheat levain that I maintain at around 100% hydration. After reading posts by Tom (Toad.de.b)  and MC (Farine)  on the mixed flour blend used by Gérard Rubaud, it seemed this would be a place to start in order to get a better flavor. I adjusted the levain flour blend to the same as in the final dough. For the autolyse, I used only the wheat flours (AP, bread and whole wheat), mixing in the rye and spelt together with the levain because I am not sure if the additional enzymatic activity would make the dough too slack (aha, another experiment!).
The loaves baked very much like other levain loaves that i have made with similar hydrations (about 72-73%) with nice blooms and singing crusts.
The comparison loaves were made with the same formula except for using a 30 min. autolyse instead of the overnight refrigerated autolyse, and I did deviate slightly by shaping them into 500g loaves instead of the 1000g ones above.
The flavor was definitely more intense on the loaves that were autolysed for around 16 hours. Compared to breads I made in the past using a straight wheat levain with the same flour blend, the flavors were more nutty and wheaty. Also, the texture was much more creamy on the longer autolysed loaves and the crumb highly gelatinized (the photo doesn't do it justice).
This is all consistent with what others have been saying. I've been just a little slow on the uptake here.
The formula, which is scaled to two 1000g loaves after baking, is below:
I'm very happy with these loaves, and I plan to try them again upping the hydration to around 78%. The other questions that still need to be answered are whether long autolyse with rye and spelt negatively affect the dough, and what is the difference between the refrigerated and room temperature autolyse used as an enzymatic preferment.
[Edit: Replace formula panel because some lines in Method were incomplete.]