Sulphite‐binding power of wines and ciders. II. Theoretical consideration and calculation of sulphite‐binding equilibra

The Law of Mass Action is used to explain the SO 2 ‐binding behaviour of carbonyl compounds in wines and ciders and to calculate the contribution of each carbonyl compound to the SO 2 ‐binding power of the system. On a model wine the calculated graph of bound SO 2 with increasing concentration of free SO 2 agreed closely with experimental determinations. Fractionation of the model wine on a column of Dowex 1 (bisulphite) gave good recoveries (95 to 103.5%) of the individual components.