What do you think you are gaining by having the mash pH at 6 compared to a normal mash pH? The article states that clove flavor is enhanced during the acid rest by having a higher pH, but I do not see where having the pH high for the whole mash helps. I like hefes to have a bit of acid zing or tartness which would favor a lower overall pH once you finished the boil. Just wondering what you are tasting compared to a lower pH.
I don't think I'm gaining anything, but I know I'm getting a more authentic Hefeweizen. Contrary to popular belief, this style is one of the most difficult to nail. I can brew a clean pils lager with no off flavors all day any day, but I've had my share of struggles trying to brew a Hefeweizen that comes anywhere close to what you would find in Bavaria. Not until I found the linked article and began brewing based on the info contained therein did I finally start producing Hefeweizens that were somewhat close to the real deal (not there yet, but I feel like I'm getting pretty close).
Let's break it down...
Per the article...
"It has been observed that an acidified mash results in lower quality estery aromas [Her05]."
An acidified mash is going to result in a lower pH, right? I mean, that's the entire point of adding acid. If I'm after estery aromas (banana), then according to the article I do not want to acidify my mash. Using relatively soft water and the typical grain bill for a Hefe (50-70% wheat malt + pils + (maybe) some Munich and/or CaraMunich) is going to result in a mash pH of around 6.0). You can lower the mash pH naturally by doing an acid rest, which will decrease esters and increase clove, but there is absolutely no reason to acidify the mash beyond that and doing so will likely be a detriment. You understand the the point of the acid rest is to create acid to lower the pH of the mash naturally, right? The Germans are not adding acid to the mash, they're getting it naturally from the grain. If you add acid on top of what is generated during the acid rest, you are taking the mash pH too low to get the flavor profile that is desired from the style. If you want more banana than clove, you forego the acid rest and go with the high pH mash. If want more clove, you do a nice long acid rest to lower the pH to mask the esters. If you want a balance, you do a shorter acid rest, so you get both clove and banana. Under no circumstances should you be adding acid from any other source.
I like a little tartness to my Hefe's as well. Fortunately, we don't need an acidic mash to achieve that.
Again, per the article...
"Wheat beer yeasts generate a high pH drop during the fermentation resulting in a satisfactory beer pH even if the wort pH was unfavorable high."
Traditional Hefeweizen yeasts tend to yield a tart beer. Some more so than others. That tartness you may find desirable in the final product is produced by the yeast, not the pH of the mash.
The article aside, my own empirical observations confirm that a high mash pH makes for a more authentic Hefeweizen. I used to target a mash pH of 5.2-5.4 using the typical salts and acid malt or lactic acid and the result was no banana and no clove. I often utilized an acid rest and still could get no clove whatsoever. Talk about frustrating. It wasn't bad beer, but it wasn't a Hefeweizen. Not until I stopped treating my water (where I live, the municipal water is about as close to RO that you can get and still be considered "drinking" water) and started ignoring my mash pH, which according to the water calculators, should have been around 5.9-6.0, did I start getting results that were more in line with the style.