Finings are substances that are usually added at or near the
completion of the processing of brewing wine, beer, and various
nonalcoholic juice beverages. Their purpose is for removal of organic
compounds; to either improve clarity or adjust flavor/aroma.
Specifically, the removed compounds may be sulfides, proteins,
polyphenols, benzenoids, or copper ions. Unless they form a stable
bottom sediment in the final container, the spent finings are usually
discarded from the beverage along with the target compounds that they
The How: Neutralising Charges
The electrostatic types comprise the vast majority. Their purpose is
to selectively remove proteins, tannins (polyphenolics) and coloring
particles (melanoidins). They must be used as a batch technique, as
opposed to flow-through processing methods such as filters. Their
particles each have an electric charge which is attracted to the
oppositely charged particles of the colloidal dispersion that they are
breaking. The result is that the two substances become bound as a
stable complex; their net charge becoming neutral. Thus the
agglomeration of a semi-solid follows, which may be separated from the
beverage either as a floating or settled mass.
The How: Absorbtion
Although activated carbon may be implemented as a flow-through filter, it is also commonly
utilized as a batch ingredient, which later must be separated and
discarded from the beverage. It can completely/partially remove
benzenoid compounds and all classes of polyphenols non-specifically,
decolorizing and deodorizing juices and wines.
The How: Enzymes
The enzymatic finings are pectin and pectinase. They aid in destroying
the large polysaccharide molecule named pectin,[clarification needed]
which otherwise causes haze in fruit wines and juices. They are among
the few finings that are added before juices are fermented.