Kaiser

Recipes 

I’m familiar with A.J.’s approach of adjusting pH after testing it. But I do think that the relation between grist composition and water chemistry are predictable enough that one can design water to get close enough to the desired mash pH. The target for mash pH is fairly large and it takes quite significant water or grist changes to be off far enough to warrant a fix. I like the fact that I can predict my mash pH when I design the recipe and don’t have to mess with pH adjustment after dough-in. This is easier for my style of brewing but it may not be easier for other brewers.

As for using water with an RA or close to 0, this will work for more beers than you think. Just look at figure 1 of the article. Most beers had a distilled water mash pH (RA=0) that was either in the preferred range or in the acceptable range. I don’t know how Tasty measures pH, but I consider a room temp mash pH of 5.1 – 5.2 a bit low. Beer quality should be the determining factor but from a technical point of view you may run into problems with the amylases once the pH drops below 5.2. Especially when you use lots of the enzymatically weaker Munich malts.

One of the motivations of this work was to provide an updated formula for the SRM based RA estimation that John Palmer made popular with his spreadsheet. In addition to that it also provides insight into why so many beers can be brewed w/o the need for water adjustment.

Kai

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GilaMinumBeer

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Kai.

First time seeing your xls. Want to play with it to see how th result fare against another sheet I have been using. How would I modify the acids section to accomodate 75% phosphoric?

Kaiser

Recipes 

Phosphoric acid is a difficult acid to incorporate due to the fact that it reacts with calcium and precipitates some of calcium phosphate salt. But that already happens anyway and not all of the Ca you have in the water ends up in the wort. I would have to experiment with phosphoric acid to see if I can simply accommodate it like any other acid.

But there is an unintended consequence with phosphoric acid that most brewers are not aware of. While it allows you to lower your mash pH, it strengthens the buffer capacity of the wort and as a result the yeast may not be able to lower the beer pH as much as it would be able to do otherwise. This concern is raised in some of the technical books I have where the added phosphates don’t come from phosphoric acids but acid rests or low pH mashes. But it should be the same for phosphoric acid additions. It would be interesting to evaluate the beer pH from 2 beers brewed with the same mash pH but one used phosphoric acid and the other used lactic acid.

Kai

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BrauKaiser.com - recipes - Blog - German Beer Reviews - Water and mash chemistry spreadsheet

GilaMinumBeer

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Interesting. I found taht I had to get away from Lactic Acid because on the lighter beer I find myself brewing as of late I was getting a twang in the finished product. Even the wort carried this twang.

Which went away once I started using Phosphoric acid. My, undereducated, guess is that I was using so much LA to get to my pH target that the flavor threshold was surpassed.

Of course, I also treat my sparge water. I was finding that it took sveral ml of Lactic Acid to go from 9.3 to a pH of 7 whereas it takes but a couple ml with the phosphoric.