Tartaric stability
Subtractive techniques
Finally a reliable answer to tartaric stability. For too long one took inspiration from tables derived from theoretical calculations based on model solutions, which matched up badly with the reality in the winery.
The answer is membrane tartaric stability (electrodialysis: Reg. EC 1493/99 Annex. IV, Art. 4(B)), which can be used for all types of wines (IGT, VQPRD, DOC and DOCG). The treatment takes place at room temperature and ensures the stability of wines while preserving the colour and structure.
Traditional solutions always make reference to the use of cold: it is important to accelerate the growth of crystals in the crystallisation nuclei of micronised potassium bitartrate. Another approach is represented by Cristallite®, a complex product also designed to facilitate the formation of nascent crystals.
Prevention techniques
It is known that Araban® and EV Gum slow the growth of bitartrate crystals.
For white and rosé wines carboxymethyl cellulose is available in 12.5% liquid form (V CMC L) and in powder form (V CMC). It is a very efficient coadjuvant. The only limitation to its use is the negative interaction that it can have with the polyphenolic matrix: for this reason carrying out a preliminary laboratory test is recommended if you wish to use it in red wines.
The use of metatartaric acid with an esterification index not lower than 40 is normal: Meta V®.