Potassium bitartrate precipitation inhibition

In other work, Moine-Ledoux et al. (1997) reported that the use of Mannostab at doses ranging from 15g/hL to 25g/hL inhibit potassium bitartrate precipitation (Table 5.2) while excess amounts of this additive, that is 30g/hL, are ineffective on potassium bitartrate crystallization (Table 5.2). Within the extracts, compounds responsible for the stabilizing effect observed were found to be highly glycosylated mannoproteins of molecular masses ranging from 30 kDa to 40 kDa possessing a glycosyl-phosphadityl-inositol anchor (GPI) (Moine-Ledoux and Dubourdieu 1999, 2002,2007). 

Table 1.19. Inhibition of potassium bitartrate precipitation by various metatartaric acids (Peynaud and Guimberteau, 1961)...

There are many laboratory tests for assessing the effectiveness of a metatartaric acid preparation. Table 1.19 presents an example of a procedure where a saturated potassium bitartrate solution is placed in 10 ml test tubes and increasing quantities of metatartaric acid preparations with different esterification numbers are added. This inhibits the precipitation of potassium bitartrate induced by adding 1 ml EtOH at 96% vol and leaving the preparation overnight at 0°C. Only 1.6 mg of a preparation with an esterification number of 10 is... 

Potassium is the dominant cation in wine, as it is in all plants. Concentrations are between 0.5 and 2 g/1, with an average of 1 g/1. Wines made from grapes concentrated by noble rot have the highest potassium content. Red wines contain more than dry whites due to the capacity of phenols to inhibit the precipitation of potassium bitartrate. 

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