“The Aber Meter (Yeast Monitor) correlated well with Methylene blue/haemocytometer method for determining viable yeast counts on normal crops. It also appears to be unaffected by such conditions as high dead cells (making it more reliable then the methylene blue staining method); low pH; and trub (which can interfere with spin down methods) giving accurate, viable cell counts under all of those conditions. In addition, when the meter was compared to the wet solids, spin down method, the meter gave more accurate and more consistent pitching rates as judged by the number of fermentors pitched at target rates.”

Miller Brewing Company Milwaukee
Request a copy of paper 40, Miller Brewing Company, Milwaukee
Maca, H.W., Barney, M., Goetzke, G., Daniels, D., & Ryder, D. (1994) The use of radio frequency capacitance for the measurement of yeast viable biomass and its use in the automatic pitching of fermentations. MBAA Technical Quarterly Vol.31 pp.146-148

“The system would ensure that the proportion of the crop most suitable for yeast pitching would be retained and a record of the quantity of yeast delivered to storage vessels would be maintained. The possibility of the crops becoming enriched with contaminating particulate matter would be minimised as would the requirement for pitching yeast slurry storage capacity”

Bass Brewers Burton (now Coors Brewing)
Request a copy of paper 39, Bass Brewery, Burton (now Coors Brewing)
Boulton, C.A. & Clutterbuck, V.J. (1993) Application of a radio frequency permittivity biomass probe to the control of yeast cone cropping.

“The direct electrical monitoring of yeast viable biomass with a capacitance probe overcomes many problems encountered when using conventional methods. The method is rapid, accurate and works in most heterogeneous environments. It is particularly suited to immobilised yeast and other samples containing extra organic matter because the background effect can be eliminated. Simple operation and automation feasibility increase its suitability for practical use”

VTT Biotechnical Laboratory, Finland
Request a copy of paper 23, VTT Biotechnical Laboratory
Kronlof, J. (1991) Evaluation of a capacitance probe for determination of viable yeast biomass. Proc. EBC 1991, pp. 233-240 [Detailed study showing that capacitance is correlated with cell concentration and viability, less so with vitality (measured via ATP, glycogen]

“According to Mrs Elke Schuermeyer and Dr Andreas Ludwig from the Radeberger Gruppe Central Laboratory, The Yeast Monitor requires minimal maintenance: a routine monthly check is made to compare the Yeast Monitor reading with the live cell concentration but the instrument settings are not changed. As a consequence, the Yeast Monitor is completely integrated into the process.”

Binding Brewery, Frankfurt
Request a copy of Binding case study

“Yeast pitching systems incorporating the Aber based system are described as the best that is currently available and capable of delivering a pitching rate that is plus or minus 5% of the desired value. ”

Prof Chris Boulton and Dr David Quain
Request a copy of Paper 128 Brewers Guardian, Nov 2007