I have been thinking - probably too much - about dough temperature. Referring to Hamelman he gives the following heuristic:
WT = 4*DDT - AT - FT - ST - FF
where WT is water temperature, DDT is desired dough temperature, AT is air temp, FT is flour temp, ST is Starter temp, FF is Friction Factor which he lists as 26.
I know from recent experience that if I plug in the numbers to get water temp, that my dough will be colder than 76F (desired dough temp) after mixing. So I have been trying to get it by trial and error. That has its limitations of course. So today, I decided I would both wing it and measure and see what happened.
I made the following measurements: AT=67.1, FT=66, ST=68.4. If I plug those numbers into the formula above for a DDT of 76, I would then set water temperature to 76.5. However, I knew that would miss the mark, so instead I took what I thought would be a better water temperature by feel, and then measured it as 96.8. I know, a lot higher. Then after mixing all ingredients I measured dough temperature and got 79.5. So I overshot somewhat. Then I got to thinking - I could compute "actual" FF from my results above. So solving for FF you get
FF= 4*ADT - AT -FT -ST -WT, where ADT is my actual measured dough temperature after mixing. So plugging in the numbers you get FF=19.7. So if you go back and redo Hamelman's formula with this value for FF the result is that I should have had a water temp of 82.8.
Now, I know this won't satisfy the engineers among you because it is still the same simple-minded approach that has equal weight for each ingredient and so forth (I read the discussion with Dan Dimuzio.) And it probably won't satisfy the pure bakers among you because, well, WTF. But anyhow, it kind of satisfies me, and I'm going to go with this revised FF next time I bake.
Oh, and despite all these shenanigans, my bread came out pretty good. But I still want more control over temperature.