Calcium tartrate problems

In addition to deposits of crystalline potassium bitartrate, infrequent calcium tartrate deposits occur in wines. The calcium level of carefully produced wines is seldom high enough to cause stability problems. Occasionally, however, wines may extract calcium from improperly prepared filter materials. Prolonged storage in uncoated concrete tanks also will release calcium into wine. 

Another method of acid amelioration, used to avoid water amelioration, is the addition of calcium salts for the purpose of substituting calcium for potassium ions. The resulting calcium bitartrate salts, being less soluble, increase the precipitation of bitartrate. This raises technical problems, one being that if the malo-lactic fermentation should take place subsequently, the wine may contain insufficient acidity of any kind. Another is that calcium tartrate precipitates slowly and in more finely divided form, often causing persistent hazes that are hard to remove. Often, too, this precipitation is delayed, leading to the presumption that the wine is tartrate stable. Only after it is bottled, the brilliant and supposedly stable wine may develop a delayed calcium tartrate haze and even a deposit. The calcium salt method in a refined form is used considerably in Germany but rarely here. 

In wine, simple salts are dissociated into TH and T ions. The last two tartrates (Figure 1.10) share the property of forming and remaining stable at a pH of over 4.5. On the other hand, in terms of solubility, they differ in that potassium calcium tartrate is highly soluble, whereas the tartromalate is relatively insoluble and crystallizes in needles. The properties of this mixed salt may be used to eliminate malic acid, either partially or totally. Table 1.11 shows the solubility, in water at 20° C, of tartaric acid and the salts that cause the most problems in terms of crystalline deposits in wine. 

If used in beverages, tartaric acid must be perfectly pure and guaranteed for food use. One problem that may need to be addressed is that tartaric acid salts, particularly the calcium and magnesium tartrates, have lower solubility than citric acid. Consequently, there is a tendency for unsightly precipitates of insoluble tartrates to form in hard water, and in such conditions it is preferable to use citric acid. 

Calcium chloride Dimercury dichloride Hops (Humulus lupulus) extract Potassium acid tartrate Sodium succinate Sunflower (Helianthus annuus) seed oil Theobromine Theophylline Turpentine diuretic, chronic bladder problems Cubeb (Piper cubeba) oil diuretic, pharmaceuticals Ammonium acetate Hydrochlorothiazide Potassium acetate Sodium acetate anhydrous Trisodium citrate Urea... 

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