Washing pre-washed lettuce, trying saying that 10 times

The public seems to be bombarded with a myriad of confusing mixed food safety messages. This is to be expected as food safety is a technical discipline that is rather complicated. Let’s take lettuce for instance, should one wash pre-washed lettuce in their sink or not? The simple answer is no. This practice would simply encourage cross-contamination of the already pre-washed lettuce from the sink, an unnecessary step. Others may feel that washing their lettuce in the sink with a dilute solution of bleach would be the answer. Dilute, what is dilute and what is the magic number?   I don’t know of anyone to have chlorine test strips in their house to verify free chlorine, which would end up being combined chlorine due to the organics anyway, to measure 50 ppm. Let’s go back to science, what does the research tell us. It has been documented that simple agitation under running water for 10 minutes is a very effective means in reducing E. coli counts.  The best treatment, however, is applying 35% white vinegar directly on the lettuce and let sit for 10 minutes(1). This has been shown to dramatically reduce E. coli counts on lettuce. You’ve gotta love science.
1. CHITRA VIJAYAKUMAR AND CHARLENE E. WOLF-HALL. Evaluation of Household Sanitizers for Reducing Levels of Escherichia coli on Iceberg Lettuce.
Journal of Food Protection, Vol. 65, No. 10, 2002, Pages 1646–1650