I've played around with all of these and not entirely sure the significance (within range of 5.1-5.8ish) in the mash variations vs. post mash PH adjustments.
Same here. I lowered pH in kettle on 3 or 4 straight German beers and am not sold on it as something to keep doing. I liked the theory, but the actual results were mixed over just riding with mash pH IMO.
I strongly caution against chasing mash pH. If you have used a reliable mashing chemistry calculator, the pH is more likely to be within a tenth or two of your target. In addition, I've found that mashing pH consistently tends to correct itself toward a pH of about 5.4. So if you measure an overly low pH, it will rise during the mash duration. And the opposite occurs if the early pH was too high.
This seems to confirm the RDWHAHB mantra.
+1; I put BNW through it's paces and trust it. pH meters are wonky devices.
+2. This why I still don't (and probably won't) own a pH meter - mash pH wants to stabilize near 5.4, within reason. Nearly all the brewers who post here check mash pH and, regardless of the reading, nearly all 'let it ride'. Even Martin says that chasing mash pH is not a good thing to do. I know different maltsters put out malts on occasion that are more acidic than usual, but my results are consistently what I want with Brunwater. Just not looking to fuss over a temperamental meter that's prone to erroneous readings if not handled correctly. Who knows, never say never.