Large mineral additions significantly lowering mash PH in Bru'n Water

I'm planning to brew a west coast IPA with the "Pale Ale" profile in Bru'n water

I typically don't go this heavy on minerals, but want to give it a go.

My NYC water is very soft (similar to RO). Usually I need to add a decent amount of acid malt (4oz to 6oz per 5g) to lower PH to 5.3 (with lower mineral additions)

Base malt is mainly Pale Ale malt (3L) with a small addition of crystal 10.

Bru'n water is telling me PH will hit 5.3 purely from salt additions. I'm adding a combination of gypsum, cacl, nacl, and Epsom salt to hit the profile (with gypsum as heaviest addition)

Does it make sense that salts alone would lower PH this much and I therefore could forgo my normal acid malt addition?

 

Insufficient details.

 

Best I can say is that given enough calcium it is doable.

Roughly 200 mEq of calcium would be my guess for a 6 Kg grist with a buffering factor of 32 and a need for the grists DI_pH to be dropped by ~0.3 points.

200/3.5 = 57.143

57.143/(32 x 6) = 0.298 points of pH drop

 

Definitely. The large concentrations of calcium and magnesium in that Pale Ale profile does have the ability to reduce pH fairly low. I use RO water as my starting point and I find that I have to add a bit of baking soda to keep the mashing pH from dropping too low when I'm targeting the 300 ppm sulfate in the Pale Ale profile.

NYC water is very similar to Pilsen water. I remember sampling a very well-made pale ale from someone in Brooklyn. They used the city water and no minerals. It was free of faults, but it was bland. Having an acceptable level of flavor ions in your pale ale does make a real difference. 300 ppm sulfate may not be your preference, but I'm sure that your note a real difference if you bring the sulfate level to around 200 ppm. The good thing is that if you brew to 200 ppm, you can test if you'll like 300 ppm better by adding a thin pinch of gypsum to a pint of your finished beer and mixing it in. That's adding about 100 ppm sulfate. If you like it, great. If you don't, your entire batch is still enjoyable.

 

To answer a couple questions which I presume may come up:

1) How many grams of Gypsum is 200 mEq of calcium ions?
2) How many grams of CaCl2 is 200 mEq of calcium ions?

CaSO4.2H2O MW = 172.17
CaCl2.2H2O MW = 147.01
Ca++ MW = 40.08
Ca++ EQ Wt. = 20.04

200/20.04 = 9.98

For Gypsum:
172.17/9.98 = 17.25 grams

For Calcium Chloride (as the dihydrate):
147.01/9.98 = 14.73 grams

172.17/147.01 = 1.171

147.01/172.17 = 0.854

To substitute or switch between them, or to use a blend of some of each:
1 gram of Calcium Chloride Dihydrate delivers the same amount of Ca++ ions as does 1.171 grams of Gypsum.
1 gram of Gypsum delivers the same amount of Ca++ ions as does 0.854 grams of Calcium Chloride Dihydrate.

0.755 grams of anhydrous Calcium Chloride delivers the same amount of Ca++ ions as does 1 gram of the dihydrate.