Originally Posted by truebe
I'm just wondering if there is any reason for people to try and replicate a city's alkalinity with salts if you're just going to be removing it in the mash anyway with little acid additions.
There are occasions when one might want to do this but they are few and far between. They usually relate to the desire to be authentic i.e. to start with water (and, presumably, to the extent possible, other raw materials) that are as close as possible to those used by a particular brewery to brew a particular beer using procedures as identical to what was done in the particular brewery as possible. In such a case you go to the considerable trouble to prepare a volume of water that has the same chemistry (it's usually possible to get within 1% for each ion's concentration) as the original water and then process it in the same way. If the processing involves neutralizing bicarbonate with acid then it is much easier to simply add salt(s) with anion concentration equivalent to the bicarbonate (e.g. if the alkalinity is 2 mEq/L and you use sulfuric acid you add 2 mEq/L sulfuric acid and wind up with 2 mEq/L sulfate).
It is also possible that some beer somewhere may have residual bicarbonate flavor as part of its profile. I am not aware of such a thing but I suppose it is possible.
Generally, trying to duplicate a city's profile is a losing proposition because
1. Many of the profiles are seriously in error.
2. You have no idea as to how the brewers using that water treated it if at all.
3. Synthesis almost always requires that chalk be dissolved with carbonic acid thus mimicing nature's way. This is a big PITA.
4. It is often possible that you can make a better [insert name of style here] than the brewers of [insert name of town associated with that style]. The good burghers of that town were stuck with the water they were stuck with. You can do anything you like starting with RO/DI.