I did pretty well in chemistry (no organic, though). I've been brewing in my current location for about 8 years now. With pretty good success. My municipal water report indicates 80 mg/L of Ca and 127 mg/L alkalinity. So, the alkalinity number explains why I have to acidify nearly every brew (with the exception of stout) with phosphoric acid (2.5 mol) to reach target mash pH= 5.4. I also acidify sparge water to pH=5.6.
I've recently been reading the Water book in the brewing elements series and playing with a brewing water calculator (brewers friend). I've observed something that I don't quite get.
When I bring up a 'balanced profile for water target' in a water calculator, say for an american amber ale, it'll give a target for effective carbonates in the range of, say, 100 ppm. Keep in mind, in this exercise, we are not trying to duplicate the water of some locale. We are looking for the 'ideal' brewing water for the style (in as much as that exists) as if we were going to build from scratch (RO water). Now, what I observe is that no matter what I add or take away, in terms of minerals, if I hit that effective carbonate concentration, I always have to acidify. And the calculator shows that when I acidify, it reduces the alkalinity, and, consequently the effective carbonate concentration reduces. Now, I realize that when you acidify, the actual carbonate concentration doesn't change. It's just a titration. You're adding acid to rebalance equalibrium to a different pH.
My fundamental question is this: why are we having all those effective carbonates in there to begin with if we have to nullify them (acidify) to reach the target pH=5.4. Are all these carbonates important somewhere in the brewing process (and for the life of me, I can't see where)? Except in the case of very darks like stouts, wouldn't it be better to not have the carbonates to begin with and then not need to acidify? Shouldn't the 'recommended effective carbonate level' be: just enough to balance the mash pH=5.4? And just experiment with a given recipe to find that point?
I suspect that the reason this thought experiment won't work has to do with buffering. In the boil. In the fermenter. But could someone with a firm understanding elighten me?
I've recently been reading the Water book in the brewing elements series and playing with a brewing water calculator (brewers friend). I've observed something that I don't quite get.
When I bring up a 'balanced profile for water target' in a water calculator, say for an american amber ale, it'll give a target for effective carbonates in the range of, say, 100 ppm. Keep in mind, in this exercise, we are not trying to duplicate the water of some locale. We are looking for the 'ideal' brewing water for the style (in as much as that exists) as if we were going to build from scratch (RO water). Now, what I observe is that no matter what I add or take away, in terms of minerals, if I hit that effective carbonate concentration, I always have to acidify. And the calculator shows that when I acidify, it reduces the alkalinity, and, consequently the effective carbonate concentration reduces. Now, I realize that when you acidify, the actual carbonate concentration doesn't change. It's just a titration. You're adding acid to rebalance equalibrium to a different pH.
My fundamental question is this: why are we having all those effective carbonates in there to begin with if we have to nullify them (acidify) to reach the target pH=5.4. Are all these carbonates important somewhere in the brewing process (and for the life of me, I can't see where)? Except in the case of very darks like stouts, wouldn't it be better to not have the carbonates to begin with and then not need to acidify? Shouldn't the 'recommended effective carbonate level' be: just enough to balance the mash pH=5.4? And just experiment with a given recipe to find that point?
I suspect that the reason this thought experiment won't work has to do with buffering. In the boil. In the fermenter. But could someone with a firm understanding elighten me?