12 hours ago, Smithy said:1. On the one hand, my bread courses have all said that ideally salt should be added after the flour, water and yeast (or sourdough starter) have been allowed to sit together, because salt interferes with yeast growth and development. Yet these articles say that salt helps with the gluten formation. That seemed contradictory at first, but after some thought I think I've resolved the apparent conflict. Salt is necessary but timing is also important because of two opposing effects on two very different factors: yeast growth and gluten development. Do I understand those two issues correctly?
That is the inescapable conclusion to the late salt adder's logic. But not everyone's on board the late salt train. The observational evidence is substantial that, while salt definitely slows yeast activity in dough, adding it earlier in the mix doesn't seem to be detrimental to the yeast in the slightest. Yes, salt is anti-fungal, so, while I wouldn't personally add salt to the yeast and water (I know many who do), as far as yeast impact goes, I see no difference between fully mixed and proofing dough, and mixing the flour and salt into the water at the same time.
Another aspect to late salt is that, while a 70-80% hydration bread dough can comfortably dissolve salt added after the flour has hydrated a bit, your typical 60%ish pizza dough can have issues. It's not like a salt covered pretzel. Most people don't enjoy hitting a pocket of undissolved salt in dough. It can also cause problems with stretching and launching.
In a high water preferment where the water activity might accelerate the yeast's anti-fungal properties and where you want fermentation to run wild, sure, no salt there. But, once you're making the final dough, I think late salt is both unnecessary and a potential can of worms.
Now, late oil... if you're working with an exceptionally rich dough... maybe 8% oil or more, then that can seriously impair gluten development unless added later.
12 hours ago, Smithy said:2. I'm surprised at the statement that a pH of 5 - 6 is ideal for gluten development, and this makes me wonder what commercial bakers do, if anything, to compensate. City water is generally controlled to around a pH of 7 (maybe slightly less) and the EPA drinking water standard is a pH range of 6.5 - 8.5. Do bakers simply give the gluten extra time and/or mechanical activity to compensate? Perhaps the optimal gluten development pH isn't that important because there are workarounds.
I was a bit surprised by that 5-6 pH level statement as well so I did some research.
https://www.cargill.com/salt-in-perspective/salt-in-bread-dough
"all doughs, not just sourdoughs, contain acidifying bacteria which contribute to the bread¹s flavor"
"A typical dough has a pH low enough (approximately 5) for the gluten protein to carry some positive charge."
And
https://www.foodelphi.com/bread-making-presentation/
"Initially, dough has a pH of about 6.2, and during fermentation, the values are about 5.76 or 5.67"
Also
http://www.fao.org/3/a-au108e.pdf
"Fermenting dough has a pH between 5 and 6"
The second link has no author listed, but, the other information in that presentation seems to reveal a fairly extensive level of technical knowledge. The third link (FAO/United Nations) seems to be reputable and that doesn't reference sourdough at all.
So... neutral water + slightly acidic flour (6ish) + time = pH between 5 and 6. In other words, and, if you're not sitting down, you might want to be 
, all bread is technically sourdough, it's just that natural leavening ramps up bacterial activity and combines it with acid friendly strains of wild yeast.
I also believe carbonic acid is a bit player in the pH equation, from the CO2 dissolving in the water fraction of the dough (most likely in small amounts). Dough isn't seltzer (between 3-4 pH), but I think it's a small step in that direction.
