pH of Dark Munich Malt (Global Malt)

In preparation for brewing a Dunkel with 99% Dark Munich malt (12L), I measured the pH in distilled water to know what to expect for a mash pH and provide the correct alkalinity by blending my tap water with RO water for the mash (100% RO water for sparge). Here is the result:

Global Malt Dark Munich Malt (12L) = 5.30
http://www.midwestsupplies.com/dark-munich-malt-global-malt.html

The pH meter was a Hanna pHep5 with fresh 2-point calibration, no significant drift in the minute it took to sample and rechecked with the calibration solutions.

What's the alkalinity of your water ? If it is 50 or less you should be fine without any RO/DI. If it is higher, dilute with enough RO water to get it down to about 50. If you want a higher pH use more tap water and less RO. Try some test mashes.

ajdelange said:

What's the alkalinity of your water ? If it is 50 or less you should be fine without any RO/DI. If it is higher, dilute with enough RO water to get it down to about 50. If you want a higher pH use more tap water and less RO. Try some test mashes.

Click to expand...

It's 350 ppm as CaCO3 (Ward test from 2011). The TDS of that test was 478 ppm and I measured TDS this weekend of 430 ppm, suspect the water is pretty consistent year-round.

I also tested 25% & 50% blends of tap water with this malt and those would be both be ok but would error on the lower alkalinity the first time.

I'm slowly measuring the pH of the base malts that are available and am using repeatedly. There are many beers where the base malt % is so high that knowing that pH in distilled water alone is enough to decide on how to target the desired mash pH.

DSmith said:

It's 350 ppm as CaCO3. I also tested 25% & 50% blends of tap water with this malt and those would be both be ok but would error on the lower alkalinity the first time.

I'm slowly measuring the pH of the base malts that are available and am using repeatedly. There are many beer where the base malt % is so high that knowing that pH in distilled water alone is enough to decide on how to target the desired mash pH.

Click to expand...

Thank you for doing the work! When you're done, if you want to post your results as a "cheat sheet" for people like me, that would be awesome!

DSmith said:

It's 350 ppm as CaCO3 (Ward test from 2011). The TDS of that test was 478 ppm and I measured TDS this weekend of 430 ppm, suspect the water is pretty consistent year-round.

Click to expand...

That's pretty hefty and, I assume, accompanied by substantial hardness.

DSmith said:

I also tested 25% & 50% blends of tap water with this malt and those would be both be ok but would error on the lower alkalinity the first time.

Click to expand...

I'm a little surprised at this given the amount of alkalinity. Of course you didn't say what you are shooting for. 5.4 is a good target. I guess I wouldn't be too surprised if you got that low with a 50% blend but that is still 175 ppm alkalinity. One caveat that goes with malt DI pH measurements is that the pH rises over 15 - 20 minutes or more. This makes measurement of DI pH tricky and measurement of malt buffering capacity even trickier especially where you are concerned about the stability of the pH electrode.

DSmith said:

I'm slowly measuring the pH of the base malts that are available and am using repeatedly. There are many beers where the base malt % is so high that knowing that pH in distilled water alone is enough to decide on how to target the desired mash pH.

Click to expand...

DI pH is half the story (and you have to be sure you have waited long enough that you are seeing the real malt pH). The other half is buffering capacity. You are mixing two buffers. The water and the malt. It is, mathematically, like what happens if you connect a pair of bars which are mechanically constrained to remain parallel with two springs of different lengths (pH's) and spring constants (buffering capacities). The distance they wind up apart (pH) depends on the strengths and spring constants of both but the stronger spring dominates.

25% tap water for this test resulted in about 5.4 mash pH (room temp). Right or wrong, I generally correlate the color of a beer to mash pH (lighter color, 5.4ish, darker, 5.5ish). Repeat brewing and changing that one parameter would be the only way to know.

I'm grinding my test mash pH malt to a dust and mixing with an immersion blender (wisk) in a mason jar - generally am seeing test mash pH's that are more inline with mash pH's at 60 minutes. If I duplicate the water & grain plan for the actual mash, I'm not surprised to see a lower pH at 10 minutes.

DSmith said:

25% tap water for this test resulted in about 5.4 mash pH (room temp).

Click to expand...

That I can believe.