Answer :Nothing short of cooking will guarantee that E. coli on produce has been killed, but some research does suggest vinegar washing can reduce contamination of fresh produce. Research at the University of Nebraska led scientists there to recommend soaking produce in full-strength white vinegar for five minutes, stirring occasionally. Rinse with clean tap water to remove vinegar flavor. Wash only what you need immediately, as washing earlier could give remaining bacteria time to grow. But Mike Doyle, PhD, director of the Center for Food Safety at the University of Georgia, cautions, We have conducted studies using vinegar to kill E. coli 0157 in produce and found this pathogen was tolerant to acetic acid (the acid in vinegar) at concentrations that would be practical for use. I dont believe vinegar is a reliable treatment, especially for leafy greens.