The implication of yeast in debittering of spent hops

The research on degradation of hop bitter acids by Candida parapsilosis culture under various conditions is described. The effects of temperature and age of precultures were investigated. Supernatant of the precultures, growing cells and resting cells of the cultures were used for the tests. The highest levels of degradation were obtained in experiments performed in the light, at 40 °C, using a 3-day-old preculture of the yeast. Efficiency of the degradation was determined by concentration of riboflavin in the C. parapsilosis culture. Commercial hop extract and spent hops were used in the experiments.