E337: Sodium Potassium Tartrate
Main role: acidity control
Also listed as: potassium sodium tartrate, Rochelle salt
What is E337 (Sodium Potassium Tartrate)?
E337 is a tartrate salt containing both sodium and potassium. Its identity distinguishes it from sodium-only and potassium-only tartrate preparations. In a food context it is used for a defined technological acidity-control purpose.
What does it do in food?
Its main role is acidity control. Acidity regulators adjust or buffer pH. The resulting acidity depends on the whole recipe, not just the presence of one acid or salt. Acidity control may also affect texture and the performance of other ingredients.
Food and formulation examples
- Specified acidity-control preparations
- Selected food formulations
These examples describe formulation roles, not a list of unrestricted legal uses. Availability and permitted applications differ by country and food category.
Label names and ingredient questions
Look for E337, E 337, or the ingredient name. Related names and label terms include potassium sodium tartrate, Rochelle salt. A family code can cover more than one specified form; check the full declaration when the distinction matters.
Rochelle salt is another name for the compound, but a laboratory product carrying that name is not automatically food grade. Specifications and intended use remain essential.
Is E337 safe?
There is no meaningful personal risk estimate from an E number alone. Food-grade specifications, allowed uses, amount consumed, and individual circumstances all matter. The authorization record below gives the legal scope; it is not a claim that every possible use is appropriate.
A label identifies the ingredient but usually not its concentration. Calculating daily intake requires the amount in the food and the quantities eaten.
Authorization and conditions of use
The Great Britain food additive register lists E337 as Sodium potassium tartrate. This is an entry subject to its stated conditions, not unrestricted permission for every food. The record links to the applicable authorization terms. For an EU product, use the European Commission food additive database to check the relevant food category and limits. Other countries may use different names or rules.