For most people, the dishwasher is a true godsend — a domestic blessing in the form of a tangle of wires, plumbing, and racks, all housed in a waterproof cube that fits neatly under the counter. You load your dirty dishes, flatware, glasses, and other kitchen implements inside, add a bit of soap, turn it on, and walk away. In about two hours, it’s all squeaky clean and dry, ready to be used or stacked neatly in the cupboards for the next snack or meal. It affords such a tremendous convenience that for many home buyers or renters, the absence of a dishwasher is a total and complete deal breaker: they’ll find a more modern place to live, thank you very much.
And while it’s tempting to stick every food soiled plate, pot, pan, cup, and anything else in the dishwasher to let it work its magic, there’s a slight catch: you really can’t put everything in the dishwasher. In fact, there are some things that you absolutely should not put in the dishwasher. It’s sad, but it’s also quite true, so don’t throw away your trusty sponge, dish soap, and drying rack just yet.
Here are ten things you should never put in the dishwasher.
1. Silver flatware.
Stainless steel forks, knives, and spoons will get cleaned up well in the dishwasher, but if you’ve got real silver, it should be hand washed. Dishwasher soap can ruin silver’s beautiful shiny finish and actually leave it more tarnished, and if you stick tarnished silver in the dishwasher hoping for it to come out clean, well, you’re in for a huge disappointment. Silver is one of those things that you still need to clean the old fashioned way: use silver flatware dip, polish it with a cloth, or use a combination of aluminum foil, hot water, and baking soda to chemically remove the tarnish.
2. Anything plastic.
Plastic storage containers are certainly convenient, and their reusability is certainly eco friendly, but washing them in the dishwasher is problematic. First of all, dishwasher detergent can dull the look of plastic, especially if it’s clear. But even more of an issue is the high heat of the drying cycle, which can warp plastic, especially if it’s on the bottom rack close to the heating element. In fact, plastic lids falling through the racks and onto the heating element have caught fire, leading to a huge and dangerous mess. It may take a little extra time, but save yourself the worry and hand wash your plastic containers.
3. Good sharp knives.
Butter knives are OK in the dishwasher, but your good chef’s knife, your bread knife, your favorite paring knife — all of these should get washed by hand. Dishwasher soap can dull the blade of good knives, making cutting more difficult and potentially dangerous (since you’re more likely to slip with a dull knife and cut yourself). Also, the heat of the drying cycle can warp and loosen the handle, which means the blade won’t be as stable.
4. Wood cutting boards and utensils.
Dishwasher soap is harsh on natural materials like wood. Repeated washings in a dishwasher will scratch things like cutting boards and wooden spoons, eventually ruining them. Plus, the high heat of the drying cycle is no friend to wood; it can cause warping, and with repeated cycles, the wood will eventually crack and split.
5. Good China plates.
After a dinner party, the last thing you want to do is wash dishes. However, if you’ve served your meal on good China plates, you’ll probably need to. The force of the water in a dishwasher, along with the abrasive detergent, can chip and scratch fine China plates, and the heat can wear out and fade decals or any hand painted details. Whether they’re heirlooms or the high quality dinnerware you got for a wedding present last year, hand wash your good China.
6. Insulated cups and mugs.
If you value your coffee on the go and you like it to stay hot for a while, hand wash your insulated travel mugs. If you wash them in the dishwasher, water can get into the insulation layer, ruining it for good.
7. Crystal glasses and bowls.
Between the abrasiveness of most dishwasher detergents and the intense heat of your dishwasher’s drying cycle, good crystal is prone to chipping or cracking in your favorite kitchen appliance. The only exception is newer crystal produced with more modern methods — check the manufacturer’s recommendation, but that should be OK in the dishwasher. Just make sure it’s secure in the top rack before turning the machine on.
8. Cast iron pans.
With proper and diligent seasoning, cast iron pans can become a favorite nonstick cooking vessel in which to prepare just about everything from eggs to steaks to a big veggie stir fry. The problem with cast iron is that you have to be extremely careful about how you clean it — and you absolutely should not clean it in the dishwasher. The detergent can strip away your carefully built up seasoning, leaving you with a sticky mess the next time you try to cook with your favorite heavy duty pan. Repeated washings in the dishwasher can also cause rust.
9. Teflon and other nonstick pans.
The abrasive dishwasher soap plus the extra hot drying cycle can destroy the nonstick coating on your Teflon pans. This renders you with a pan that’s either completely unusable or one that has a loose coating that can end up in your food — and you absolutely should not ingest these chemicals! Even if your nonstick pan has a label indicating that it’s dishwasher safe, it’s really best to not take chances; just take a few minutes to wash it by hand in the sink.
10. Aluminum pans.
Lots of people like aluminum cookware because it has a lovely shiny finish. However, dishwasher detergent can oxidize aluminum, making it look dull and old and anything but shiny. If you’re an aluminum user, keep those pots and pans out of the dishwasher.