Sodium tartrate (Na2C4H4O6) is a salt used as an emulsifier and a binding agent in food products such as jellies, margarine, and sausage casings.

As a food additive, it is known by the E number E335.

It is made by the combination reaction of baking soda/Sodium Bicarbonate (NaHCO₃) with tartaric acid.

Because its crystal structure captures a very precise amount of water, it is also a common primary standard for Karl Fischer titration, a common technique to assay water content.

This article about an organic compound is a stub.