Do dishes used for preparing food need to be washed with soap?

Question

It seems to me that washing dishes with soap serves two purposes:

1. To remove food residue from the dishes
2. To kill bacteria that got on the dishes

As far as I know, the primary way bacteria get on dishes is from coming in contact with human saliva. But that wouldn't happen with dishes that are used exclusively for preparing food and not for eating it. So, assuming good residue can be removed without soap, is there any benefit to washing dishes used for preparing food with soap?

For the purposes of this question, assume we are talking about a home kitchen and not a restaurant.

Answer 1

Human saliva is not your only concern. There are a variety of pathogens that could be problematic if food preparation items (hands, utensils, cutting boards, counter tops, and containers of all sorts) are not properly sanitized. This includes potential pathogens that already exist on the raw food itself. Soap is not necessarily required, but some type of sanitizer is. Dish soap just happens to also remove grease, and is most commonly found in the home kitchen.

Answer 2

"Assuming food residue can be removed without soap"? It's a lot easier with soap (or detergent, which I guess would be the same diff).

If you go to the effort of thoroughly cleaning all food residue, including grease, off of the dishes, with just plain water, then yes, I think the pathogens, microbes, other germs etc. would be washed off along with the food residue. Regular soap, or detergent, isn't really intended to be a germ killer anyway, unless you are talking about "anti-bacterial" soap. That's why you sometimes hear people recommending a disinfecting step (bleach-dip) after rinsing dishes, even when they have used soap.

So I think it actually would be effective - but more difficult - to go ahead and not use soap when washing cooking dishes in your own home with just plain water. I suppose that this is what you mean by "without soap".