This can have corrosive effects on the materials of construction of HLT's if left in solution. Magnesium Magnesium is an essential element of brewing liquor because it is required by yeast as a co-factor for the production of certain enzymes required for the fermentation process. It is invariably formulated into liquor treatments at relatively low levels. Excess magnesium can interfere with the reactions of calcium because its phosphates are more soluble 2. In excess magnesium has a laxative effect Sodium Sodium is present in all beers.
Excessive levels are undesirable as it imparts a sour and salty taste at high concentrations.
The flavour is more acceptable when the sodium is present as chloride than as sulphate. Potassium Potassium is, like magnesium, a yeast co-factor and is required at trace levels for satisfactory fermentations. It is more acceptable than sodium from a flavour point of view, giving a salty taste without the sour notes. It is also gaining some favour as Doctors warn of the effects of high sodium intake on blood pressure. However potassium salts are very much more expensive than the sodium equivalents, and in excess potassium has laxative effects.