On several different threads I've seen posts that decry ever putting good, sharp kitchen knives into automatic dishwashers. Supposedly it takes the edge off. What I don't understand is how this happens. Hand washing knives uses both hot water and detergents so how would a dishwasher that uses the same stuff cause the edge to be removed? (Curious minds want to know!)

Most dishwasher detergents have a large amount of abrasives.

You are "sandblasting" them.

Most dish soap is a surfactant and detergent and does not dull the edge.

I've always assumed the concern with edges isn't the water/chemicals but them getting banged around due to water pressure. Even if just banging up against coated rack that's going to have an impact. HA! I slay me!!

Also of equal concern to me is the affect of chemicals on the handles, whether wooden or composite. Even a few runs would likely dull those, and repeated washes I assume would have a pretty harsh affect on them.

Interested to see what the experts say.

1- The heat from the dry cycle MIGHT draw the temper.
2 - This couldn't be good for the handle - especially if it's wooden.
3. The edge could bang against other things.

Why not just rinse it off, dry it, and run it across a steel a couple of times? It takes less than a minute and you're GTG for the next time it's needed.

Higher carbon steel knives will rust in crazy patterns and will need to be polished to remove. I know I put one in the DW thinking it was a s/steel. Chris

I have my dish washer knives. They are all metal Kitchenaid with no seems for water to intrude. Still, I give them 20 strokes each side on the steal every time I take them out of the dish washer. Thus they stay acceptably sharp and I have no worries about the wife or kids destroying them.

quote:

Originally posted by Jim Shugart:
1- The heat from the dry cycle MIGHT draw the temper.
2 - This couldn't be good for the handle - especially if it's wood.
3. The edge could bang against other things.

Why not just rinse it off, dry it, and run it across a steel a couple of times?

Right on the money.
Modern dishwashers are pretty harsh thus whatever you put in there need to be able to withstand the temps and the pounding from the water jets. Combine with the abrasives of the detergent, you basically have a hydraulic scouring mechanism. Put an aluminum sheet pan in the dishwasher, it'll blast the tin surface coating right off and likely warp it permanently.
Knives are your most important kitchen tool, they along with the cutting boards should be hand washed immediately or, soon after usage. One, for safety issues, nothing like an exposed blade wobbling around the counter while you're trying to work, and of course sanitation.
I usd to work at Williams-Sonoma on the weekends so I could stock up my kitchen, every week there was a housewife who would come in and reveal a knife that was put into the dishwasher thinking it was ok. The culinary students who worked there would either run into the back stock laughing or, just shake their heads while bitting their tongues as they knew, if a student ever did that in their classes, there would be hell to pay.

I've always thought that banging the sharp edge up against other metal utensils in the rack was the problem but the wooden handles on many don't do well in the harsh environment too.

I toss them all into the dishwasher. If they need to be sharpened then I sharpen them. NBD.

That said, you can trash a handle beyond repair if it's not dishwasher safe. The extremely hot steamy water and harsh soap will turn some woods to crap, so keep an eye on what you have and how it looks until you know how it's going to go. I have expensive handmade Japanese knives that do fine, but have also trashed a commercial chefs knife that I figured would be plenty tough (it was wood handle and wasn't tough enough).

Mainly handles that will delaminate and good knives being of higher carbon content.

All of my knives can go into the dishwasher. I only use Kyocera Evolution ceramic knives.

Mine go in the dishwasher. I just don't buy expensive knives.

There is some potential for abrasive wear from detergent and dirt particles.

The edges can easily be banged into the racks and other utensils.

Rust. (Even on stainless.)

All that water is not good for wood and some other handle materials. Likewise the high heat of the drying cycle. My mom has some lovely wood-handled Dansk flatware from the late '50s. The wood handles are shot, and she probably doesn't use it but three times a year.

I don't think the dryer gets hot enough to hurt the steel.

How long does it take to hand wash a knife? 30 seconds?

quote:

Originally posted by corsair:
Modern dishwashers are pretty harsh thus whatever you put in there need to be able to withstand the temps and the pounding from the water jets. Combine with the abrasives of the detergent, you basically have a hydraulic scouring mechanism. Put an aluminum sheet pan in the dishwasher, it'll blast the tin surface coating right off and likely warp it permanently.

Your definition of modern dishwashers must be different than mine. Modern dishwashers take 3.5 hours to "wash" your dishes because of all the energy efficiency bullshit, and don't achieve the temperatures and flow rates that they used to.

I live in a less than 2 year old home with all energy efficient appliances, and I was shocked at the changes in the dishwasher from a 2008 dishwasher.

I no longer worry about putting my plastic handled drop forged Henckels in the dishwasher and can maintain an edge with a few swipes on my sharpening steel.

the dog will cut his tongue on them when he goes to lickin the silverware

My wife killed a very nice, rather expensive Japanese chef knife. The edge of that knife, while exquisitely sharp, was very thin and very hard. Banging around in the machine with other items resulted in many, many small chips to the edge. The handle was also damaged by the heat.

I bought her a set of Victorinox knives (which honestly are pretty great cutters) and gave her strict instructions to not use my knives unless she wanted me to start laundering her delicates.

quote:

Originally posted by copaup:
My wife killed a very nice, rather expensive Japanese chef knife. The edge of that knife, while exquisitely sharp, was very thin and very hard. Banging around in the machine with other items resulted in many, many small chips to the edge. The handle was also damaged by the heat.

I bought her a set of Victorinox knives (which honestly are pretty great cutters) and gave her strict instructions to not use my knives unless she wanted me to start laundering her delicates.

Very well handled.

quote:

Originally posted by jimb888:
I toss them all into the dishwasher. If they need to be sharpened then I sharpen them. NBD.

This.
I've had *1* wooden handle go bad and crack...after 20 years of use and dishwashers. I just bought a new replacement and that one will go in the dishwasher too.

That dishwasher can't hold a candle to what my wife will do with the knives.

I have some Gerber Balance Plus from the '80s that my Dad's caregiver put in the dishwasher. Blades are fine, handles are OK but not near
as nice as they could be.

We always hand wash working knives. Several reason for this. 1. it only takes a few seconds to run a soapy cloth across them, rinse and towel dry and 2. since there is currently just the two of us, we only run the dishwasher every second or even third day and we need the knives pretty much every day. All that and it seems most people advise against the dishwasher for good knives.

On the other hand, I've had a few arguments....err spirited discussions with Mrs Navy over putting certain items in the dishwasher, but that's another thread.