Am I calculating my ph right?

[Silver_Is_Money]

A.J., I believe have resolved my buffer issue. When my (admittedly inferior to Solver) static buffer value is set at 50 (where I get the best matches to your values) and when I set up 'MME' to match your scenario for the mashing of both 10 lbs. and 30 lbs. of DI_pH 5.6227 base malt into 11 gallons of 95.4545 ppm alkalinity water, with zero ppm's of Ca++ or Mg++ present, I now get the following as output:

1) For 10 lbs. the mash pH for 'MME' is now 5.9739 (whereas formerly it was something like 6.17, and whereas you reported getting 5.96 via Solver)
2) For 30 lbs. the mash pH for 'MME' is now 5.7398 (whereas formerly it was something like 5.81, and whereas you reported getting 5.7432 via solver)

RPIScotty, my buffer no longer seems to be causing any downstream problems with regard to alkalinity matching well with baking soda, such that the two are properly interchangeable (mEq for mEq). The only difference of significance which I see now is attributable to my implementation of A.J.'s formula to compensate for the weak dissociation of baking soda within the range of mash pH's. No interference with lactic acid addition quantities matching up with negative alkalinity either.

 

[Silver_Is_Money]

Mash Made Easy's solution to the OP's recipe is now anywhere between 7.83 to 8.41 grams of baking soda, depending upon what value I set the buffer at, wherein my buffer value range has (for now at least) been limited to 30 to 50.

At 50 the answer to the OP's recipe is 7.83 grams of baking soda to hit a mash of pH 5.4.
At 40 the answer is 8.05 grams.
At 30 the answer is 8.41 grams. (which is the same answer I had gotten previous to this modification)

 

[Big Monk]

Mash Made Easy's solution to the OP's recipe is now anywhere between 7.83 to 8.41 grams of baking soda, depending upon what value I set the buffer at, wherein my buffer value range has (for now at least) been limited to 30 to 50.

At 50 the answer to the OP's recipe is 7.83 grams of baking soda to hit a mash of pH 5.4.
At 40 the answer is 8.05 grams.
At 30 the answer is 8.41 grams. (which is the same answer I had gotten previous to this modification)

It’s tough to help you troubleshoot I guess when it’s unclear what this “buffer value” actually does.

 

[Silver_Is_Money]

Since there is no alkalinity in the OP's mash water, you are only seeing the effect that the buffer has with respect to the downward shift in mash pH due to added mineralization for the example of the OP's recipe.

The pre baking soda addition mash pH is in the range of 5.15-5.16.

But remove the added minerals from the mash water and the pH jumps up to 5.19-5.20. And the suggested baking soda addition for this later case is ~6.95 grams.

 

[ajdelange]

There are other sources of alkalinity in this mash namely the base malts. Changing their buffering values changes the downward shift in pH of the mash induced by the dark malt in exactly the same way it changes the ability of hydrogen ions from the calcium reaction. The appeal of this method is that all mash components, water, bicarbonate in the water, grains, added bicarbonate, the water itself, added acids (strong or weak), added bases other than bicarbonate, H+ from Ca++ are all treated in the same way. Their individual proton deficits or surfeits WRT a trial pH are added together. The mash pH is the trial pH that makes that sum 0.