I like the idea of acidulated malt adding brightness/flavor as my lighter beers have been good, but not great, lacking brightness or pop sounds about right.
The 'bright flavors' come from getting the pH into the right range irrespective of how you do it. Using sauermalz instead of phosphoric, lactic, sulfuric or hydrochloric acid adds the unique flavors of sauermalz which has it's own flavor profile as does any specialty malt. As I noted in an earlier post, its flavors are quite subtle.
So I'm not arguing Beer 4 or 5 would be better. I'm just not getting the numbers I expected. When I plug the numbers for Beer 4 into Brunwater using 2.65 grams/gallon calcium Chloride, I get an estimated PH of 5.1. This seems low.
The 2.65 grams/gallon number would get you a drop of 0.3 pH relative to a distilled water mash using Kolbach's nominal number. But Kolbach's number is a nominal number for base malt only presumably lager base malt. 5.1 does seem low. It suggests that the base malt pH would be 5.4 and that's not reasonable for pale malt. We need to re-emphasize that Kolbach's number is a nominal number and that the drop actually refers to the drop in kettle pH relative to a distilled water mash. As there is usually additional pH drop in the kettle we would expect the drop in mash pH to be less than 0.3.
The ideal mash PH range varies by author and I have noticed a trend that the ideal range may be getting higher. I read older articles that suggest 5.1 to 5.3, newer articles I am seeing 5.2 to 5.4, 5.3-5.5 or wider ranges like 5.2-5.6. Recently I watched a video of John Palmer recorded a few months ago and he was suggesting 5.4-5.8.
Have you noticed this trend?
There has been a lot of confusion over this as much of the older literature (with the exception of, for example, deClerck), does not specify whether pH values are referred to room temperature or mash temperature. In the professional literature it is usually safe to assume that laboratory temperature is being used because in the days this literature was written there were no pocket pH meters. Mash and wort sample were transported to the lab for analysis and were either cool when they arrived or were cooled when they got there. Home brewers tended, conversely, to think of mash pH in terms of mash temperature. Some of us have been making a big fuss about this in the last few years pointing out that the professional literature referred to lab temp and that it is useless to say 'mash temp' unless yoy say whether that means in the cold, a beta glucan rest temp, protein rest temp... That may have had little influence but when we pointed out that measurement at mash temperatures would shorten the lives of their electrodes home brewers began to listen. I think the 'trend' you have observed may be caused by this rather than by thinking that mash pH should be higher than previously thought.
What is your opinion on ideal range?
When people ask that question I often note that I went to a 3 day conference in Belgium a few years back and the session was titled 'The pH Paradox'. The paradox is that there is no ideal pH.
Should the ideal PH vary by style?
I rather think it is like any other parameter such as mash temperature. It would probably be best to brew a particular recipe at different values of mash pH,
ceteris paribus, to see whether any particular pH gives better results than others. I will say that I think the best target for the beers I brew (German and Bohemian lagers) is 5.4 - 5.5. As I don't do other styles that often I can't comment as to whether a higher pH is, for example, desirable in ales. In brewing texts you will sometimes find higher targets in German books and lower ones in British books.
Being a lighter colored beer are you making the mash more acidic than normal for the brightness?
Do I add more acid? Yes - because there is very little acid in pale malt and more external acid must be added to hit a particular pH than would be the case with a darker beer in which the dark malts supply some acid. If you are alluding to the charts, calculators and spreadsheets which indicate that a certain RA is 'required' for a beer as dictated by its color depth (SRM) try to forget that you ever saw that.