Measurement of HGB beer colloidal ageing and tannoid content development using complex turbidimetric analysis.

Comparison of hazes in freshly bottled and aged beers by multiple angle turbidimetry

“…It is well known that freshly filtered and packed beers are initially bright, but with time they become hazy due to the light scattering effects of chill and permanent haze particles which develop during the storage (Smythe et al 2002;Sladký et al 2004;Sladký 2005). The statement holds particularly for pale lager beer types packed in transparent bottles in which the haze or clarity of beer can be directly inspected and evaluated visually by the customer or consumer (Smythe et al 2002;Clark & Bamforth 2007).…”

“…Besides the hazemeters or turbidimeters which determine the haze at scattered light angle either 90° (Buckee et al 1986;Sladký et al 2004) or 13° (Mundy & Boley 1999), there are at present in the current use the so called dual (scattering) angle hazemeters which enable the determination of haze in beer not only at the scattering angle of 90° but also in the forward direction of scattered light, usually in the 11° to 25° range (Klimowitz & Byrnes 1994;Sladký 2005). The dual angle hazemeters have been proved to be very useful for the control and evaluation of filtration technology efficiency (Klimowitz & Byrnes 1994) because, when standardised by formazin suspension (Webster 1983;Morris 1987), they can detect more effectively the presence of coarse haze particles larger than several micrometers (e.g.…”