Potassium sodium tartrate

Potassium sodium tartrate, also known as Rochelle salt or Seignette salt, is a double salt of potassium and sodium derived from tartaric acid, with CAS number 304-59-6. It is supplied as a colourless aqueous solution and serves as a chelating and buffering agent across food, pharmaceutical, and personal care applications.

In food processing, it functions as a sequestrant and pH buffer, stabilising emulsions and preventing metal-catalysed oxidation in dairy and baked goods. In pharmaceutical compounding, it is a key component of Fehling's solution, where it chelates copper ions to maintain reagent stability. Personal care formulators use it as a skin conditioner and mild protectant in topical preparations.

Potassium sodium tartrate is available in food-grade and pharmaceutical-grade forms, compliant with FCC and Ph.Eur. standards where applicable. It is subject to REACH registration requirements for European supply. Packaging formats typically include drums and IBCs for liquid grades.