Ultraviolet light and brewing.

Whitby, E.

Abstract
The use of ultraviolet (UV) irradiation to disinfect water for brewing avoids the cost, addition, removal and disposal of chemicals with the need for complex mechanical dosing systems and the danger of over-dosing. It is more energy efficient than heating or boiling water and no corrosive or scale forming compounds are formed. The presence of dissolved materials or iron in water to be treated can adversely affect the performance of UV equipment by precipitating out on the quartz sleeves and by adsorbing UV light. Water composition must therefore be taken into account when calculating dosage and setting cleaning schedules. The major disadvantage of UV disinfection is that it does not add a residual to the water to prevent microbial growth in the water distribution system. For this reason the UV system should be located as close as possible to the point of use. Advice on equipment design and dosage calculation, is given. Emphasis is placed on the importance of applying sufficient UV radiation to kill undesirable organisms. Additional applications for UV equipment include its installation before the activated charcoal filter to reduce the chlorination requirement, to disinfect dilution, rinse and push water, on water circulation equipment, in cooling towers and to treat make-up water for yeast cultures.
Keywords : brewing disinfection light microorganism treatment ultra-violet water