- Pasteurizer, sterilizer
Sterilizing heating equipment used to kill off yeast and hi-ochi kin, and to deactivate remaining enzymes. There is the simple jakan apparatus, double-pipe heat exchangers, multi-pipe heat exchangers, and the most common, plate-type heat exchangers.
Double-pipe equipment works by heat exchange between the liquid flowing in the inner and outer pipes. Although inexpensive, this system has the disadvantage of a small area available for heat exchange. Multi-pipe equipment uses small-bore brass or stainless steel piping housed in a shell, and heat exchange takes place as sake is passed through the piping.
Plate heaters consist of 1-2mm stainless steel or titanium plates set up in sequence with dividing gaskets, with the space between each plate becoming the fluid passage. The sake-containing plates are alternated with those holding steam or hot water to permit heat exchange. As the spaces between the plates are only a few millimetres wide, the area of heat exchange in relation to the volume of liquid is extremely large, allowing high levels of heat exchange efficiency and a small surface area for the equipment.