Homogenous solution for the analysis of bitter acids in beer.

The sensorial perception of beer is mainly defined by the quality and the properties of the raw material used during brewing, such as the choice of the hop. Hop can be purchased in the form of hop powder, pellets or extract (acid and oil). It has multiple functionalities during the production of beer. Serving as an antimicrobial function, the hop is added to the boiling wort. It also helps stabilize the foam in the beer and is responsible for the well-defined flavour perception and the bitterness of the beer. The bitterness is characterized by the acid profile of the hop, defined by alpha-acids (humulones) and beta-acids (lupulones). During boiling in the wort, the alpha-acid molecules are volatilized or oxidized and isomerized to iso-alpha-acids. These iso-alpha-acids are responsible for the bitter taste of the beer. The standardization of the hop quality is therefore crucial to obtain a constant beer quality, where the alpha-acid concentration is set to 15, 30 or 60% in hop extracts. The analyses of the acids are an important step to guarantee high and persistent quality. Various analysis methods are available, but the main used are gas chromatography and conductometry. Conductometry is a low-cost method and therefore often utilized. Alpha-acid analysis requires a homogenous hop solution produced under highly efficient mixing to avoid the disintegration of the alpha-acids into their thermal sensitive derivates, iso-alpha-acids. PT-G 30/2 X So in combination with PT-D 36-60 from Kinematica provides a solution to this problem.