Why is it bad to put knives in the dishwasher?

[TheCook]

Why is it bad to put knives in the dishwasher?


I've been putting my Wusthoff knives in the dish washer for a while now, I'm not sure if I see any difference. The chef knife needs sharpening but I'm thinking thats because I use it 85% of the time over the other knives.

[GB]

There are a few reasons.

1. If they have wood handles then the prolonged water exposure, temps, and detergents can destroy the handles. If the handles are not wood then they could still be damaged by these things. I believe the plastic Wustoff handles are safe in this area, but I could be wrong.

2. Inside a dishwasher during a washing cycle can be a turbulent and violent place. Items can get knocked and tossed around. You run the risk of something slamming into your blade and damaging it.

3. Because things can move around, when you open the dishwasher and reach in you run the risk of cutting yourself as the knife may have moved to a position you were not expecting. Ganted, this one is a minor one because most people do look at what they are doing and do not just blindly reach in, but still it deserves to be mentioned.

What I am not sure about is how the heat affects the metal. I am sure others will jump in here and answer that and also point out other reasons I may have missed.

the bottom line though is that if you are happy with the results you get from running them through the dishwasher then keep doing it. The knives will not turn to dust on you.

For me, I find it so quick and easy to wash a knife in the sink right after I use it that I would find it less convenient to have to put it in the dishwasher and not have it available for use until the washer has been turned on.

[CharlieD]

I wish my English was better so I could explain all the technicalities of heat exposure to a knife. Hopefully there are people here who could do better job than I can. Basicaly, heat is not good for a heat treadted material.

[sattie]

I put my crud knives in the dishwasher and hand wash the good ones.

[Mama]

I handwash all of my knives and hone them before each use (probably isn't necessary...just a habit)

[pacanis]

Same here (as Sattie). And since all but one of my knives is a crud knife, and I never use my Chinese knife, everything goes in the DW. That's going to change soon though.....
And even though they are crud knives, I still put them someplace so something isn't bumping into it the whole time. I always look when I unload the washer. I'm missing a big piece off of a 23oz draft glass that has me paying extra attention, so it does get rough in there.

[bowlingshirt]

Originally Posted by sattie

I put my crud knives in the dishwasher and hand wash the good ones.

This is what I do. I've also heard that the detergents can be tough on the blade.

[buzzard767]

Originally Posted by GB

What I am not sure about is how the heat affects the metal. I am sure others will jump in here and answer that and also point out other reasons I may have missed.

It doesn't. The max temperatures reached in a dishwasher are 140-180F. Blade tempering takes place in the 300-400F range. However, detergent chemicals might affect the steel but I doubt they are exposed long enough for this to take place.

Buzz

[gadzooks]

Hand wash and dry after each use. Hone or steel as needed. Most of my knives have wooden handles, and I like 'em. I have some by the same maker with nylon handles, made specifically so they can be washed in a machine. I hand wash those and dry 'em after each use, too. I don't have a dishwasher. In fact, the handles are raw (unsealed) walnut, so I occasionally oil them a bit. Keeps 'em nice. I have a bunch of good knives, and keep whatever I'm currently using in a block or on a cutting board on the counter. Storing them in a drawer is bad for most of the same reasons as washing in the DW. Accidental impalement, and the edges can get beat up. I am guilty of drawer storage, I will admit. When I take a knife out of the drawer, I check the edge before I use it.

[reesecook]

Mainly is because of the knives handle. Anyway, I would recommend to hand wash your knife and dry it quickly even it's dishwasher safe, this will help to maintain your knives better.