THE FLASH PASTEURISATION OF BEER

Abstract

The theory of beer pasteurisation is discussed in terms of thermal death time and logarithmic death. Over‐pasteurisation can adversely affect flavour and the control of temperature and holding time which is necessary in order to minimise such effects is described. A temperature control band of 3°C and a holding time such that the fastest material through the system is just pasteurised are recommended. Overall pasteurisation plant design is then considered including flowsheet configuration, heating method and automatic control system. The heat exchanger is the single most critical item in the system. Its specification including materials of construction, mechanical design features and pressure rating are discussed and recommendations are made regarding the prevention of corrosion‐induced failures by monitoring chloride levels in operating fluids and by regular inspection and replacement of plates. Finally, data on capital and operating costs are presented and the optimisation of a typical pasteuriser is described. It is shown that the extra capital cost of increasing heat recovery to 95% can usually be justified. 1984 The Institute of Brewing & Distilling