Beer Haze

Several substances can cause haze in beer, but the most frequently encountered problem is due to a cross-linking of polyphenol and protein. These materials probably exist in equilibrium in beer and manifest themselves as a haze when the polyphenol polymerizes. The proteins particularly involved in haze are rich in proline. A range of stabilization treatments—of relatively low cost— is available, but the avoidance of haze problems (which seem to be occurring with increased frequency) demands a holistic approach from the brewer in which all stages from raw material selection to final processing are geared to achieving prolonged shelf life.