Can You Wash E. Coli Off Produce?

Photo: Kimi Harris.

There was another spinach recall last week, with spinach being pulled off the shelves in 39 states. I personally enjoy a variety of raw greens, but I have been concerned with the many recalls in recent years. I wondered how effectively you could wash or treat spinach and lettuce greens at home, so that if the greens were infected with E.coli, you'd be able to safely consume it. Here is what I learned.

You Can't Wash E Coli Off

In a general bacteria count test that Cook's Illustrated conducted, a diluted vinegar wash proved to be the most effective in reducing bacteria counts. In the magazine's testing, they used a 3-1 ratio of water to white vinegar. Kept in a spray bottle, you can easily mist produce like apples, and then rinse them off under cool water. For something like spinach, a soak in a vinegar/water solution using the same ratio is recommended.

I was encouraged that a simple vinegar dilution rinse was just as effective, if not more, than the expensive produce washes found at the store! It is also worth noting that a good rinsing with water was also effective in reducing bacteria counts, though not quite as effective as the vinegar rinse.

But what about E. coli specifically?

Here is where it gets a little tricky. E. coli can make you sick even when present in very small amounts. So while it is significant that a vinegar rinse could reduce the E.coli counts, there is a chance that you could still get sick from any lingering bacteria. Even more disturbing, E. coli can can create a biofilm once it has attached to produce, which makes it hard to wash off. To top it off, E. coli can penetrate deep into the tissue of the vegetable or fruit, making it impossible to wash off.

What You Can Do

So what can you do?

  • You can cook everything, which kills E. coli. We really enjoy sautéed spinach, for example, and it seems easier for children to digest than raw.
  • You can keep track of recalls. This will prevent you from eating a possibly contaminated food item in your refrigerator.
  • Buying from small-time farmers, who are isolated from the bigger agricultural environment, can be helpful in reducing your chances of food poisoning. I don't think there is any hard data to support this claim yet, but it's worth thinking about (and, besides — you get to support local farmers this way!).
  • You can use the vinegar rinse to reduce bacteria counts, which could prevent you from getting sick if the bacteria counts were low to start with.
  • Health officials in Canada mention that it is the immune compromised who are most at risk from E. coli. (Most who encounter E. coli don't experience the most serious side effects.) Working towards a strong immune system is one of the best first-line defenses from experiencing the worst symptoms of E. coli poisoning.