Ca salts and mash pH stability

[sixhotdogneck]

In the 1939 paper the authors state (pg. 382):

Lastly, calcium salts have the effect of slowing down the liberation of inorganic phosphate and the attainment of a stable value of ph during mashing.

Several questions arise from this statement:

1.) Would mash pH stabilize faster if Ca salts were added to the boil instead of the mash.
2.) Would the precipitation of phosphates be more vigorous if Ca salts were added in the boil.

References:

Barley Phytin in Malting and Brewing (1948)
REACTIONS BETWEEN THE MINERAL SALTS OF BREWING WATERS AND CONSTITUENTS OF MALT (1939)

 

[sixhotdogneck]

In trying to edit the above post I'm getting an error message stating that the edit is spam however I can assure you that the following change is indeed not spam:

2.) Would the precipitation of phosphates and phytates be more vigorous if Ca salts were added in the boil.

 

[ajdelange]

Given that the basis thesis is correct I'd have to think yes and yes.

 

[Silver_Is_Money]

Did I understand correctly from an admittedly very cursory and rapid scanning of the linked documents that magnesium reacts with malt phosphates but does not precipitate them out like calcium does?

And if the precipitation of malt phosphates is in fact of positive benefit, would this less than desirable result (the failure to precipitate out the phosphates) be one more nail placed in the coffin of adding magnesium minerals to the mash water?

 

[ajdelange]

The magnesium phosphates are more soluble than the calcium phosphates and do not precipitate, therefore, to the same extent. That is why effective hardness is the calcium hardness plus half the magnesium hardness.

The benefit of hardness is not that it reduces phosphate but that it produces pH lowering protons in the process.The naive brewer tries to control pH with calcium additions and the doubly naive one with magnesium but it is half as effective. Magnesium is more typically used as a way to get more sulfate.