Mash pH vs. target profile

[petrolSpice]

I got my brew water tested so now I want to try to target a water profile and mash pH. Here is my current understanding of the process, please correct me if I'm wrong...

I add salts of various kinds to hit the desired level of ions as best I can. There is some give and take here since a single salt contributes to more than one ion. The salts also adjust the mash pH slightly.

After I get the profile looking good, then I add acid to achieve the desired mash pH? I can use acidulated malt or lactic acid to do this.

So the mash pH is based on the mash water volume and water profile is based on the batch volume?

I am a no-sparge BIABer, so hopefully that makes everything a little simpler.

 

[dpeters]

Down load Bru'n water.
https://sites.google.com/site/brunwater/

 

[petrolSpice]

Down load Bru'n water.
https://sites.google.com/site/brunwater/

Way ahead of you.

The issue is that if I add lactic acid to get the appropriate mash pH then the bicarbonate levels are negative when I'm looking for about 110 ppm. So I add baking soda or pickling lime and it helps the bicarbonate but now the mash pH is way off again...

EDIT: So I did a search and it seems like bicarbonate is nothing to worry about. If this is true I wonder why it's part of the target profile?

 

[ajdelange]

I add salts of various kinds to hit the desired level of ions as best I can. There is some give and take here since a single salt contributes to more than one ion.

If your desired profile is realistic it is possible to come very close to it but to do so you will have to use a method more sophisticated than what the popular calculators do. That is built into Excel in the form of the Solver but you have to know how to use it and most people seem to be terrified of it for some reason.

But then it isn't really that important to have a 'profile'. Broad similarity between the water traditionally associated with a style is sufficient.

The salts also adjust the mash pH slightly.

After I get the profile looking good, then I add acid to achieve the desired mash pH? I can use acidulated malt or lactic acid to do this.

You can use sauermalz, sauergut, lactic acid, sulfuric acid, phosphoric acid etc but bear in mind that each acid contributes an anion (lactate, sulfate, chloride, biphosphate....

So the mash pH is based on the mash water volume ...

The mash pH depends on the relative acidities/alkalinities of the mash components one of which is the water

and water profile is based on the batch volume?

It is generally simplest to treat all the water the same but that isn't always possible.

Just starting out you will probably do yourself a favor by just adding some calcium chloride and/or calcium sulfate to RO water. See the Primer. As people seem to like less salts in their beers than they did when it was first written use half the amounts it recommends.

 

[petrolSpice]

If your desired profile is realistic it is possible to come very close to it but to do so you will have to use a method more sophisticated than what the popular calculators do. That is built into Excel in the form of the Solver but you have to know how to use it and most people seem to be terrified of it for some reason.

I have the Excel solver working with Bru'n Water to minimize the sum of the squares of the errors plus the sum of the additions. Works okay but it's hard to "teach" it the qualitative importances.

 

[ajdelange]

EDIT: So I did a search and it seems like bicarbonate is nothing to worry about. If this is true I wonder why it's part of the target profile?

Martin, in each of his profiles, wants you to have so much calcium, so much magnesium, so much sulfate... When he tots that all up he comes up way short on anions. So what is he to do? Add bicarbonate to balance. But the amount of bicarbonate depends strongly on the pH. So he sets pH to 8.3 (where bicarbonate peaks). This renders the profiles pretty useless IMO unless you take out the bicarbonate and an equivalent amount of calcium. You are now back to a balanced profile which, presumably, is relevant WRT chloride, sulfate and sodium.

 

[ajdelange]

I have the Excel solver working with Bru'n Water to minimize the sum of the squares of the errors plus the sum of the additions.

Good on ya! A suggestion: minimize the sum of the squares of the logs of the ratios of the realized to target concentrations. This will put errors on an equal footing on a percentage (geometric) basis rather than an arithmetic one. A one percent error in realizing a chloride level of 10 is 0.1 mg chloride whereas a 1 percent error in shooting for 300 sulfate is 3 mg thereof.

You can also weight the log ratios going into the sum so that, for instance, if you really want a particular level of chloride and don't care so much about the sodium you can emphasize chloride error at the expense of sodium error.