Botrytized wines chemical composition

These results suggest that non-Saccharomyces species may contribute significantly to the fermentation of botrytized wines. C. zemplinina seems not to produce excess volatile compounds nor any specific aroma compounds (Toth-Markus et al., 2002). Its main contribution to the chemical composition might be an increase in glycerol content and in the G F ratio. C. zemplinina and C. stellata have proven to be very fructo-philic yeasts (Mills et al., 2002 Magyar and Toth, 2011 Magyar et al., 2008). 

The unique chemical composition of botrytized must greatly impacts the products and by-products of alcoholic fermentation, as well as subsequent reactions. The changes have been extensively studied by German and French authors and have been reviewed by Dittrich (1977, 1989), Jackson (2008), Ribereau-Gayon et al. (2000), and Dittrich and Grossmann (2011). The chemical composition of some traditional (German and Hungarian) botrytized wine styles are illustrated in Table 6.5. 

TABLE 6.5 Chemical composition of some traditional botrytized wines from France, Germany, and Hungary... 

Experts from the OIV estimate that the concentrations recommended by the EC can be decreased by 10 mg/1, at least for the most conventional wines. In this perfectly justified quest for lowering SO2 concentrations, specialty wines such as botrytized wines must be taken into account. Due to their particular chemical composition, they possess a significant combining power with sulfur dioxide. Consequently, their stabilization supposes extensive snlfiting. The EU legislation authorizing 400 mg/1 is perfectly reasonable, but this concentration is not always sufficient. In particular, it does not gnarantee the stability of some batches of botrytized wines and will not prevent them from secondary fermentation. 

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