Silicates can be extracted from malt husks. High levels can cause slow runoff and haze in beer. Silica can combine with calcium and magnesium to produce heavy scale in pipes and can foul reverse osmosis membranes

Common Values for Silica

  Barley Malted Barley Wort US Tapwater Pilsen Water Burton-on-Trent Water Brewing Targets Levels in Beer
Silica ... ... 40-210 ... 4-6 16-35 0-250 120-500

 

Silica levels in malt from various malthouses

 

Silica variation by variety*Note - Havener is a hull-less type barley, so naturally is lower in silicates, which are largely found in the hull.