Beer haze may also be addressed during maturation (pre-filtration) using precipitants. Proteolytic enzymes such as papain can be used to remove (hydrolyse) haze proteins, although the enzyme can also have a negative impact upon finished product, as it is relatively non-specific and often hydrolyses foam active proteins to destroying a beers head. However, research conducted by Eden et al (2005), using a proline specific protease enzyme (from the microorganism Aspergillus niger), resulted in the prevention of chill haze in beers without having a negative impact on the foam active proteins, as they are very low in proline. This enzyme may prove to be a viable option for brewers in the future.
Tannic acid (a polyphenol) interacts with HA proteins to form insoluble precipitates in the beer. These precipitates are frequently voluminous, thus beer losses via this mechanism can be large.
Fining with agents such as gelatine can also remove HA protein.
Microbrewers often rely on the more traditional method of extended cold storage and filtration to precipitate and remove HA material, which can result in a less stable product.Tags:beer, beer clarity tannic acid