Tag Archive: chemistry

So after the low mash efficiency last few beers AND my perception (note 1) of low mash efficiency in my last beer, I started looking at water more.

After looking at my options, I found a page on Braukaiser, and ended up purchasing an aquarium test kit that tests GH, KH, pH, NO2, and NO3.  The NO2 and NO3 are unnecessary for brewing, and I had 0 ppm for both of those anyway.  Using the spreadsheet and my 180ppm measurements for both GH and KH, I found Ca = 51 ppm and Mg = 13 ppm.

That’s not too different from my old measurements:

Ca: old 54, new 51

Mg: old 13, new 13

The two interesting differences are alkalinity and pH.

Alkalinity: old 123, new 180

pH:  Old 8.1, new 7.5.

The total alkalinity is a concern – that’s the ability of the water to buffer changes in acidity.  And my pH is lower than expected.  So I may not have had the wort in the proper pH range.  This could be why I’ve had efficiency problems.

No nitrites or nitrates. 7.5 pH, 180 ppm of both Ca and Mg.

That being typed, I need a good pH meter.  That’s really the only point that I came to after all this.

Note 1: I initially thought that I had really poor efficiency, and there is a problem somewhere in my measurements… particularly not taking a pre-boil gravity.  I have the first running and the second running and the OG, and I determined a potential amount of sugar in the two runnings and it may be okay.  The real problem was that I had far too much strike water and didn’t make any adjustments.  I DID figure out that if I use Denny Conn’s method, I can safely assume his assumption that 10 pounds of grain absorbs 1 gallon of strike water, because mine is a hair over that.

On to the next beer!