Sulphite binding in ciders

The extent of sulphite binding was measured in commercial ciders, and exper imentally observed binding curves were compared with theoretically derived curves based on assessment of the levels of individual sulphite binding com pounds determined in the ciders. Subsequently, experimental ciders were fer mented under various controlled conditions using nine different strains of cider yeasts. The results indicated considerable differences both in the le vels of sulphite binding compounds produced, and in the ability of differen t yeast strains to produce SO2 in the cider. Juice concentration and the pr esence of cloud in juice had little or no effect on sulphite binding. Other factors which affected sulphite binding included the type and condition of juice (especially the effect of pectinase treatment) and, in some instance s, the use of added yeast nutrients. Significant sulphite binding was also attributable to unaccountable components, probably derived from poor qualit y fruit, which were present in the apple juice prior to fermentation.