Natural Rochelle Salt

Potassium Sodium Tartrate is commonly called Rochelle Salt or Seignette Salt. It was discovered in 1672 by Pierre Seignette, born in La Rochelle (France). Is the Potassium Sodium Salt of Tartaric Acid.

Rochelle Salt comes from a natural crystalline acid deposited on the inside of the wine barrels at the cellars. Our Natural Rochelle Salt is a food grade product and it is FSSC 22000 certified products by SGS and it is also Kosher certified, with REACH registration number HM921428-29. The company has the registration number for the "Food and Drug Administration (FDA)", which allow us to export our goods to USA.

Manufacturing production process is followed by an exhaustive quality control guided through the expertise of our technical staff.

Rochelle Salt bag FSSC 22000

Main applications of Rochelle Salt

Used mainly in formulations for copper baths. It increases the conductivity and anodic solubility in galvanising baths.


Copper bathes containing Rochelle Salt have the following advantages:
- Increased anodic solubility.
- Possibility of working at higher current densities.
- Increased cathod efficiency.
- Greater suface uniformity.

Treatment of metals
Food industry

Production of pectines and meet preservatives.

Wall plaster

Act as retardant for plaster and cement.

Silvering of mirrors

Act as reducing agent.

Cigarette paper

Delays the consumption of cigarette paper.

Piezoelectrical effect
Pharmaceutical industry
Laboratory reagent

Used for fehling solution test and determination of uric acid.

Chemical characteristics of Rochelle Salt


- Seignette Salt
- (2R, 3R) - 2,3 dihydroxybutane - 1,4 - dioïc acid, Potassium Sodium Salt, tetrahydrate
- L(+) Tartaric Acid mono sodium mono Potassium Tartrate
- Butanedioïc acid, 2, 3 - dihydroxy -, [R(R*,R*)] -, monopotassium monosodium salt, tetrahydrate
- Potassium sodium Tartrate
- Monopotassium, monosodium Tartrate, tetrahydrate

Chemical formula

Formula: C4H4O6KNa.4H2O
Chemical formula: KOOCCH(OH)CH(OH)COONa.4H2O
Molecular mass: 282.23

Identification numbers

EC number: 206-156-8
CAS number: 6381-59-5
Merck Index number: 6381-59-5

Physical properties

Description: colorless crystals, white, crystalline powder or granular crystal
- Salty taste
- Odourless
Relative Density: D204 (Kg/l) 1.78
Melting Point: 70-80º C
Specific Rotation: [α] 20D +21º (C = 2% in water)
Descomposition at: 220º C
pH of a solution at 5% (water, 25º C): 7-8
Solubility in water: 73 g. Rochelle Salt/100g of water at 20º C. Practically insoluble in alcohol.
Crystalization system: Diamond-shaped crystals


Strength: Not less than 99% and not more than 102% C4H4KNaO6

Principal impurities: Meets the limits established in the most recent editions of the FCC, BP, USP, European Directive and the Oenology Code.

Storage - Stability

Rochelle Salt must be kept in an airtight packing and stocked in a dry place, away from humidity and in normal conditions of temperature.

It is a stable compound which does not alter with time if those advises are respected. An use by date is although given according to the regulation, it is two years.

This product has tendency to become caked therefore a long storage is not recommended especially for the powder grade.

¿Problems for viewing the PDF files? Install the latest version of Adobe Acrobat Reader.