Clarification

Egg, cheese and arabic gum. This is not a recipe, but a list of systems used in the past to clarify wine, making it cleaner and clearer. The French call this 'collage' (sticking) or fining. A colloidal compound is added to the wine and this reacts with the substances which causes turbidity in the wine.

The two substances (that in the wine and that added) have opposite charges and are attracted to each other. They flocculate, joining together, and precipitate. The wine is then racked and filtered to take out the deposit. In the wine there are positively charged and negatively charged colloids. It is therefore necessary to find colloids with the opposite charge to get rid of them. The positively charged colloids are 'neutralized' with bentonite, or kaolin, colloidal silica or tannin. Proteins are used to get rid of the negatively charged colloids (tannins) fish glue, casein (or, rather, potassium caseinate), albumen, gelatin, de-fibred cattle blood and also a type of colloidal silica which has a positive charge.

Arabic gum is suitable for preventing any type of turbidity as it envelops individual particles of colloid and does not allow reciprocal attraction, so it avoids flocculation and deposit. Arabic gum is said to have a colloid protective action.

If the slightly more of the substance than necessary is added to the wine it will form turbidity due to this excess; this is called over-fining. It can easily be seen in white wines, which have practically no tannins, when treated with gelatin.

[Return to Index]

From Santa Margherita