The calcium salt of tartaric acid, that is calcium tartrate, is extracted and crystallized from the residue left after the distillation of grape marc and wine lees. The product, as an intermediate product (intermediate) of tartaric acid production, is sold in a 1000 kg so-called "big-bags" to factories producing tartaric acid.
Calcium tartrate specification
| Name: | calcium tartrate |
| Chemical formula: | CaC4H4O6 x 4H2O |
| Color: | light yellow or light brown |
| Physical state: | powdery crystals |
| Tartaric acid content: | min. 46 m/m% |
| Moisture content: | max. 10 m/m% |