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You can find tons of tips online saying you should always wash your produce. What is the point of it though? I mean with some hard produce, say carrots you can obviously give them a good scrub with a brush and I can see how thoroughly it cleans them. What about soft produce though?

I've just read a question regarding raspberries. The answer was to wash them gently in cold water. I can't imagine that this is actually cleaning them properly. Obviously if they're very dirty, then it'd remove the biggest dirt. Let's say though that there are some bacteria on it or parasite larvea. Obviously gentle dip in cold water won't help, will it?

user3681304
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  • Actually soaking in a baking soda solution and up to 15 minutes is recommended for complete removal of pesticides. https://www.consumerreports.org/pesticides-herbicides/easy-way-to-remove-pesticides-a3616455263/ – nickalh Sep 19 '21 at 00:55

2 Answers2

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For the most part, rinsing produce in cold water is for the purpose of removing pesticides and soil that may contain bacteria. You're not washing off bacterial colonies - whole peel-on vegetables and fruit have a protective coating (the peel) which prevents them from growing for the most part. However, dirt particles may contain bacteria - particularly if, for example, there was animal manure used to fertilize the crops (one reason why you need to wash organic produce just as much as conventional produce!)

See for example the NHS England guidelines for washing produce:

Washing will help remove bacteria, including E.coli, from the surface of fruit and vegetables.

Most of the bacteria will be in the soil attached to the produce. Washing to remove any soil is, therefore, particularly important.

Of course, produce that has more dirt in it (such as lettuce, which grows in dirt) will need more careful cleaning than tree fruit (which probably doesn't have too much on it beyond pesticides).

bdsl
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Joe M
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  • Very cool, this makes sense! I actually used to think that except for grinding my teeth there is nothing wrong with some soil on my veggies... – user3681304 Sep 15 '21 at 20:24
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    It's also useful for removing bugs that are often found in fruits and vegetables. Even if eating them is usually not a problem from a health point of view, it's not most pleasant experience. – Najkin Sep 16 '21 at 07:50
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    Only if you know that you eat them, @Najkin. :) – AnoE Sep 16 '21 at 09:33
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    @Najkin -- question: what's worse than finding a worm in your apple? answer: finding half a worm. – Pete Becker Sep 16 '21 at 12:57
  • As for why **cold** water, at least for leafy veg it helps them to [crisp up](https://cooking.stackexchange.com/q/114573/34123). – J... Sep 16 '21 at 15:55
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    @PeteBecker What is even worse than that? Finding 1/4 of a worm. Even worse? 1/8 of a worm. However for some reason when I find no worm at all, I am not disgusted. – Steven Gubkin Sep 16 '21 at 20:27
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    @PeteBecker - that one _never_ gets old! – davidbak Sep 16 '21 at 23:23
  • The source of food borne contamination is often the people picking/handling produce and is a result of poor hygene (caused in turn by poor working conditions). – papirtiger Sep 17 '21 at 09:51
  • You mentioned removing pesticides, usually you'll need soapy water to do that – Rsf Sep 17 '21 at 11:11
  • @PeteBecker: Mmm, protein! – Vikki Sep 18 '21 at 00:37
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It's worth noting that from a food safety perspective, washing is not about eliminating all harmful bacteria and viruses, but reducing their amount to the extent possible (in addition to removal of pesticides, debris such as dirt, etc). Many pathogens cling to things like dirt better than fruit or vegetable skin, so even in the example of raspberries, rinsing can easily knock some dirt off.

To use handwashing as a proxy for washing vegetables, washing hands with water alone still results in a dramatic decrease in bacteria on your hands. In fact, much or most of the power of handwashing can be had with just running water and rubbing your hands together. Of course, if you have soap it should obviously be used.

Dosage is also important. In order to get sick from a pathogen, you have to come in contact with enough of it, often in the order of thousands or tens of thousands of it whether that be individual bacteria or viruses. So reduction is prevention, even if it's not perfect prevention.

Mr. T
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    Great study you linked to! I think "much" or "much or most" would be more appropriate for that link than "most". The study counted cases of diarrhoea, but not severity of cases. Maybe the drop from 12.5% to 6.9% eliminated most of the worst cases, or maybe the drop to 3.7% did. – user1521620 Sep 17 '21 at 20:00
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    @WHO'sNoToOldRx4CovidIsMurder: Maybe it eliminated all _but_ the worst cases! :-P – Vikki Sep 18 '21 at 00:38