How does malt affect mash pH in water with different pH profiles?

[Finlandbrews]

If I would mash a same grain bill in a tap water of pH 8 which would then bring my mash pH to 5.6 for example. What would happen if I would mash the same grain bill to a water of pH 5.2? What could be the pH change?

Can a pale ale malt or any malt always acidify a mash more, meaning that the pH would always become more acidicic no matter what the water pH is?

After the mash, does the boil off/evaporation reduce or increase mash pH?

 

[mattdee1]

The answers to these questions can be quite involved. Even a simple analysis would require one to understand much more than just the starting pH. A few points:

- Starting pH of water, by itself, doesn’t tell you much.
- Malt acidifies the mash and lowers pH, with that effect generally being stronger with “darker” malts.
- The alkalinity of the water – that is, its ability to “absorb” malt acidity without lowering of pH – is a key component to understand
- When grains are mixed with water, certain compounds interact with calcium and magnesium in the water, which has the effect of lowering the alkalinity (the remaining alkalinity is the so-called “residual alkalinity&#8221

I’m sure one of the experts will be along shortly to provide more details, but these are some high-level points to consider.

 

[bigdongsr94]

Yep read about residual alkalinity.