Figure 7 shows the separation of the main cations in beer
using the Dionex IonPac CS12 column. The sample was
degassed and diluted 1:40 prior to injection. Sodium
was the first peak to be eluted. At a concentration of
75–150 mg/L, it gives a round smoothness to the beer when
combined with chloride. If too much sulfate is present,
however, sodium gives an unpleasant harshness to the
flavor. Potassium is the next metal to be eluted, and like
sodium it can impart a slightly salty flavor to the beer. It
also inhibits the action of certain enzymes in mash.
Magnesium is an important nutrient for yeast at levels
around 10–20 mg/L, but imparts a sharp, bitter-sour flavor
at levels much higher than 20 mg/L. Calcium is perhaps
the most important metal, since it reacts with phosphate
in the malt to lower the pH of the mash and wort. It also
assists enzyme action, but has no effect on the flavor of
the beer.