(NWW) - Investigating the efficacy of UV-C radiation as an alternative technology to inactivate microorganisms in red and white grapes juices and wines. INTRODUCTION: Microorganisms certainly play a crucial role in wine production (Mauriello et al., 2009; Ruiz et al., 2010), however some yeasts and bacteria can have a negative impact on the quality of wine due to spoilage (du Toit and Pretorius, 2000). Good hygiene practices together with excellent winemaking procedures are recommended in the cellar to continuously control the growth of microorganisms throughout wine production.