Non-microbiological turbidity of beer: Part 1 – semireview

Abstract

Beer is a complex mixture consisting of hundreds of chemical substances. Some of them are macromolecules, such as proteins and polysaccharides that together with polyphenolic compounds form poorly soluble complexes causing beer turbidity or cold colloidal turbidity. Furthermore, beer turbidity can be caused also by procedural particles entering into beer during brewing process (filtration and stabilization aids) or by foreign particles from external environment (mechanical impurities). If turbidity, sediment or individual particles occur in filtered and stabilized beer, their origin must be determined since brilliant visual impression of the filtered beer influences an opinion of customers on a specific product. The identification of different species of turbidity using microscopic image, particle staining, enzymatic analysis or identification precursors is clearly described in this paper. The study includes pictorial documentation of various particles that may be part of beer turbidity.

Keywords

• beer
• colloidal turbidity
• protein turbidity
• protein-polyphenol turbidity
• haze
• microscopic analysis
• image analysis
• particle identification