I have a friend who assigns one knife for cutting raw meat, another knife for cutting fruits and vegetables, another for cutting cooked meat, etc. Is washing one knife after each specific use not sufficient to avoid cross-contamination? (Note: different cutting boards are assigned for different food types as well)

  • I've never even questioned this before, but now you mention it why is it OK for boards but not for knives?
    – Gary
    Mar 4, 2011 at 8:37
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    @Gary, cutting boards are different because the knife cuts in to the board, leaving grooves for food / bacteria / etc to get stuck in. It's much easier to completely clean a knife than a cutting board for that reason. Hence the reason for separate cutting boards, but not necessarily knives.
    – yossarian
    Mar 4, 2011 at 16:55
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    And it costs an extra $ to have a spare plastic board - it costs $100 for an extra knife Mar 5, 2011 at 3:35

5 Answers 5


Using separate cutting boards is advisable, but separate knives are unnecessary. 90% of my cutting is done with my chef's knife. I don't own two of these, nor would I use a subpar knife for the job.

I almost always find it most convenient to start my preparation by cutting the veggies, fruit, etc. first and then finally cutting the meat last. Then you can wash your knife once and be done with it.

  • 2
    +1. That's exactly what I do. If it's not convenient for some reason, I will just use two knives and wash both after the fact, but I don't designate knives as a meat knife outside of a single cooking session.
    – yossarian
    Mar 4, 2011 at 16:56
  • So, it's a little extreme to use different knives to avoid contamination. Thanks.
    – user5101
    Mar 7, 2011 at 7:25
  • I would suggest you should instead go by descending order of restrictions (e.g., vegan and unique allergen, followed by common allergens, then common ingredients, etc.).
    – Arctiic
    Mar 8 at 20:46

This is completely unnecessary so long as you clean your knives properly (soap, hot water for the blades).


Cutting board material is typically absorbent, whether it's wood or a knicked, scratched, sliced-up poly board. Try as you might, you can't guarantee the cleanliness of a cutting board; however, a knife blade is made of metal and doesn't retain material like a cutting board. You can therefore assure that, once cleaned thoroughly, it can be used again for different food.

  • Yes, I agree. Wood is porous and metal is not.
    – user5101
    Mar 7, 2011 at 7:09

Separate (red) cutting board for meat is a good idea.

I don't bother with separate knives BUT I just realized the only none meat thing I use a chef's knife for is crushing garlic.

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    Why don't you use a chef's knife for anything else? There's a very good reason that it's the dominant standard. Speaking as a professional, I will go days on end before reaching for anything other than the classic French knife.
    – daniel
    Mar 5, 2011 at 4:44

I agree This is completely unnecessary so long as you clean your knives properly (soap, hot water for the blades). However make sure your knives are in good working order. Loose grommets or grooves can be great places for bacteria to hide. Personally I prefer knives with commercial grade "Sani-Safe" handles.

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