Optimization of the primary fermentation technology of ‘Jinyan'kiwifruit wine

Kiwifruit‘Jinyan'is a new variety with excellent eating quality, while there were few research reports about its brewing presently.In this study, kiwifruits ‘Jinyan'produced in Pujiang city of Sichuan province were used as raw materials and the optimum primary fermentation technology of kiwifruit wine was investigated.Effects of fermentation modes, SO₂ addition amounts, yeast inoculation amounts and initial sugar concentrations on the quality of kiwifruit wine were discussed through single factor experiments as well as orthogonal experiments, with indicators including reducing sugar, total acid, p H, light transmittance, alcohol degree and sensory evaluation. The results demonstrated that the optimal primary fermentation condition was to use fruit juice fermentation, adjust initial sugar content to 23° Brix, inoculate yeast of 0.4 g/L, add SO₂ amount of80 mg/L. The primary fermentation finished after 5 d, and kiwifruit raw wine was obtained with the reducing sugar of 8.35 g/L, the total acid of 13.28 g/L, p H value of 3.43, transmittance of 94.9%, and alcohol degree of 9.11 ( v/v) , respectively. The produced wine had clear and transparent wine body, with both kiwifruit aroma and alcohol aroma. The results provided a theoretical basis for the deep processing technology of kiwifruit.