How many grams of Baking Soda will bring a mash of 1 Kg. of Sauermalz to 5.4 pH?

[Silver_Is_Money]

If 1 Kg. of a nominal acidity lot of Weyermann acidulated malt (acid malt, Sauermalz) was to be mashed all by itself in 4 Liters of DI water, roughly how many grams of baking soda would need to be added to the mash to bring it to pH 5.4?

Edit: My initial guess is ballpark 29 grams.

 

[ajdelange]

Pretty close. I get 31. Of course it's going to depend on the sauermalz. The Weyermann's I measured had pHDI = 3.62 and linear buffering term -292.09. From 3.62 to 5.4 is far enough that non linearity makes a difference. A simple linear (Riffe) estimate of the pH with 31 grams is 4.75. An improved linear estimate (which is a single step from 5.4) gives, unsurprisingly, 5.40 as the estimated pH. The square and cubic coefficients for this malt are 68.443 and -5.3985.