J. Inst. Brew. 116(4), 348-353, 2010Ultraviolet (UV-C) light irradiation is gaining rapid acceptance within the food and beverage industry as a non-thermal disinfection technique. A series of trials, using a pilot scale UV-C treatment system, were conducted to investigate the effect of UV-C on beer with specific attention to lightstruck flavour formation. Both commercial and micro-brewed beers were treated with UV-C light at 254 nm. Samples were analysed by consumer and trained panels. Sensory analyses revealed that at a low UV-C level, lightstruck flavour was apparent and this increasingly gave way to a more intense burnt rubber off-flavour as the UV-C exposure was increased. A sample enrichment probe technique coupled with a gas chromatography-mass spectrometry (SEP/GCMS) revealed the presence of lightstruck flavour in all the treated beers.