If your mash pH is 5.4 and you add the dark grains later, your final mash pH will be significantly lower, let's say 5.0.
5.0 is 2.5 times the hydronium concentration of 5.4 pH.
This alters boil chemistry, and most likely final beer, significantly vs the brewer that adjusts to 5.4 with dark grains included.
This chemical alteration is independent of the flavor impact of the dark grains before vs. end of mash.
Just for giggles on my last batch I took pH readings (again).
Grist was 78.6% Golden Promise, 11.9% Golden Naked Oats in the main mash, and 4.8% Double Roasted Crystal held to 30 min mash out/hot steep. Granted not the roastiest of grists but it was what I brewed that day.
The pH from a sample in the BK, prior to boil, cooled to 68°F: 5.4
This is why I quit taking mash pH readings. These theoretical huge pH drops from late additions of roasted malts just don’t happen in my world. Maybe it’s the qty I use or other ingredients like the distilled or RO water, the Brewtan B, or processes like YOS deaeration, mash cap, underlet, HERMS, etc. I dunno but it just works.
I will take some readings from something roastier like a Stout or Porter but I’ve done it before and found little drop (like .1) so, to tell you the truth, here’s where I’ve landed: “Once you understand your water profile and water treatments, you likely won’t worry about mash pH at all.” — G Strong.
If you get the results you like, then that's a great approach. For me, I found that adding those grains late changed the character of the beer in ways I didn't care for.
While I certainly do not doubt that we each have our preferences on how and why we do the things we do, no offense intended but…. to be fair this wouldn’t be the first time you’ve not given a fair assessment of a process without first denying it’s validity.
Well, after all the times I've told S. Cerevisiae that I've tried it and didn't \care for the results, I decided it was time to give his procedure a fair trial. Here's what happened....http://www.experimentalbrew.com/blogs/denny/old-dognew-tricks
In that post it says, “I have always told him that I've tried that and didn't care for the results. But I decided that it was time to ditch the old fogey attitude and actually give his method a try.”
So, I question you when you say “adding those grains late changed the character of the beer in ways I didn't care for”. If you have tried it — great. Maybe my taste buds aren’t properly calibrated ‘cause I really enjoy the results.
I do know five years later Mark wrote in his 09/17/2020 blog post on the Experimental Brew website: “It was like the floodgates of acceptance opened after Denny Conn gave it a shot and wrote about his experience.”
“My conclusions pissed off a lot of people who thought that the more work you do, the better beer you make. Tough. Until YOU do the experiments for yourself, you really don't know. So, get your brew on and find out!” — Denny Conn.
A year ago, after some frustrating beers that followed all the conventional wisdom, I followed your advice and ‘got my brew on’ by applying the techniques in Brewing Better Beer
. I believe they not only work but eliminate a bunch of hassles like a box full of brewing salts, spreadsheets, gram scales, pH meters, etc. Cheaper, easier, better beer than I ever brewed before (concede: my opinion).
I personally couldn’t be happier with the results but I can understand if someone tries it and decides not to employ the technique(s). …but before throwing a wet blanket on something at least “…ditch the old fogey attitude and actually give his method a try.” — Denny Conn
If anyone wants Pickling Lime, Epsom Salt, Kmeta, and bottle of Lactic Acid you can have mine. I haven’t used them in over a year. I’ve repurposed the Sea Salt and Baking Soda and want to hang on to the pH test solutions to calibrate my pH meter to test my tomato plant soil. I have a stir plate around here somewhere, too.