"I think the point is that if you adjust the water chemistry correctly the pH will be what it's supposed to be, right? Saying that you don't need a pH meter is not the same as saying that pH doesn't matter."
I don't think anybody did say pH does not matter and what is the right pH ? The correct pH is going to fall into a pH range. Using alkalinity you can hit that range without knowing the pH of your brewing liquor
Beer must have been awful before pH meters came along... eh no actually. For the avoidance of doubt I never said pH meters were useless or pH does not matter. Rather I made the point that if you have the alkalinity of your brewing liquor right a pH meter is not really needed your mash will be in the right pH range. If I had the choice between a pH meter or an alkalinity testing kit I would take the testing kit it tells you more about you brewing liquor than a pH meter does at the most important point of the brewing process.... before you start to do anything . I do have a pH meter I definitely have no reliance on it though. As I said each to their own.
I've been following the thread (lengthy read), so in summary, can you say......
Ideal Mash Ph should be: 5.4-5.6?
Ideal Pre-boil Ph should be: 5.2-5.4?
Ideal Post-boil (pre-ferment) should be: 5.0-5.2?
Ideal Post-ferment should be: 4.0-4.4?
I'd recommend downloading Bru'n Water if you aren't already using it.
You're gonna get a ton of varying opinions on here, but I think I really like Roberts post where he went through the ideal ranges for the various stages
For many years, I've brewed great beers by targeting Mash PH only. Adjusting preboil and post boil PH is a bit more advanced and only something I've been messing around with lately.
If adjusting Mash PH only, this is what you should target :
Crisp or Lighter styles: 5.2 to 5.3 (hazy IPAs, saisons, heffeweizen, wits I'd go 5.2. Pilsners, Blond Ales, Old School IPAs or things you may want to accentuate the malt a bit go 5.3). Now if you do acidify preboil or post boil, then you could mash higher on these styles, but again that's a bit more advanced and complicated.
Stouts or very Roasty beers you wanna aim 5.4 to 5.6.
5.3 to 5.4 is a good middle of the road number for most styles. Brown Ales or maltier things 5.4 is good.
In terms of salt additions, it really depends on style:
Most beers you want to get 50ppm of Calcium. The final Sulfate and Chloride content is then where you can refine thing a bit. Sulfate has a drying perception and Chloride has a malty perception.
I feel like IPAs and extremely hoppy beers are really the only styles where going extra heavy on the mineral content is worthwhile (> 100ppm sulfate)
For darker styles hitting your target PH and Calcium of 50ppm with minimal sulfate should be the goal. This generally means adding baking soda to lower PH and a touch of calcium choride to hit > 50ppm to <100ppm calcium. Skip gypsum or salts that increase Sulfate (likelEpsom) all together in these types of beers unless you are going hoppy. You don't want a drying effect from the Sulfate as roasted malts already have a drying effect.
For most other styles hitting 50ppm calcium should be one of the main goals. For very delicate things like pilsner you generally want softer water, so adding a touch of calcium Chloride to is all you should need to hit that calcium level. However if you are brewing a hoppy or extra crisp version of a lighter style going as high as 100ppm Sulfate can be desirable to give a drying sensation and help the hops pop
Bru'n water has some great preset target water profiles (yellow balanced, yellow dry, yellow malty etc)
***everything I'm saying here assumes you start with very soft water or reverse osmosis water. If you live on the east coast Poland Spring works really well if your tap source is too hard or you don't have access to RO filtered water. ***
You are best off mixing the salt additions to strike water. Solubility is more reliable when added to the water. For acid adjustments in the mash I like using acid malt as it's less of a hassle to measure than lactic acid. Lactic acid may be a touch more accurate, but probably insignificant