Beer, evaluation of final product and filtration efficiency
The concentration and size distribution of particles in beer may be measured using the Coulter Principle also known as the Electrical Sensing Zone (ESZ) method. A suitable electrolyte solution is required to perform the analysis.The sample is prepared by dissolving a certain volume of beer in the electrolyte and then analysed using a Beckman Coulter Multisizer 3 to determine the size distribution and concentration for the particles present in the beer. The results are reported as number of particles per milliliter for the desired size range.
The use of the Multisizer 3 provides a fast, easy, accurate and automatic method to determine the particle content in beer. The use of this instrument also provides reliable results not dependent on the operator’s judgment making it possible to compare data from different work shifts and/or breweries.
Significance
The determination of particle concentration in beers is
important for evaluating and/or correcting several steps
during the brewing process and finishing of the product.
■ Evaluation of the Final Product. Each kind of beer
has its own characteristics and distinctive flavor; these
properties will be influenced to some extent by the
content and size distribution of particles present in
the final product.The stability and therefore the shelf
life of beer are also affected by its particle content.
■ Evaluation of Chill Haze Effect. This is the most
common, and in some sense, the most important type
of beer hazesince it is relevant to many beer types.
As the name suggests, this haze appears when the
beer is suitably chilled; the haze disappears upon
warming. The temperatures at which the haze appears
and disappears depend on the physical stability of the
beer.The more stable the beer, the closer to 0 °C
before chill haze occurs.The haze involves complexes
of highmolecularweight proteins and polyphenols (tannins).
These compounds form weak, temperature sensitive
hydrogen bonds that are broken as the beer’s temperature
increases, allowing the resulting compounds
to form a complex with water molecules and go
into solution.
■ Filtration Efficiency. Brewers have been using
some type of filtration for centuries. If properly used,
it can serve as an effective nonadditive tool in beer
clarification. Filtration is used in conjunction with fining
agents to render beer brilliantly clear and stable
with respect to temperature changes.
In this paper we will refer to the evaluation of the
final product and filtration efficiency.
