Knowing how savvy and experienced our Cook’n readers are, I often hesitate to pass information along—thinking you likely already know this stuff. But in the off chance we have younger cooks in our readership, I’m going to share this anyway.

Today my Martha Stewart newsletter contained a helpful article explaining that there are some things that should NEVER go in the dishwasher. Article author, Madeline Buiano, prefaces the list with this: “Hand washing these things will prevent any potential damage or warping under the high temperatures and strong water pressure of your dishwasher.”

FINE CHINA, first and foremost. I's not recommended to put delicate or expensive china in the dishwasher due to the potential for damage from high water temperatures, strong water pressure, and abrasive detergents to cause color fading, delicate decorations, and hygiene concerns.

SHARP KNIVES comes next. While it's typically fine to wash butter knives in the dishwasher, steak knives, bread knives, chef's knives, and other sharp knives should be hand washed and dried with a soft towel. A main concern is the potential for warping. [Alice: It never occurred to me that sharp knives could warp in a dishwasher!]

CAST IRON—this should be obvious, right? It will rust as a result. Recommended cleaning technique? Clean it with a sponge or stiff brush and coarse salt, rinse, and dry completely. Many cast iron enthusiasts like to sit it on low- to medium-heat burner for a couple minutes to be sure all moisture is wicked away.

NON-STICK PANS—for me, this wasn’t so obvious. The professional chefs and cooks all say it’s about keeping the pan’s coating intact. High water temperatures, harsh detergents, and abrasive scrubbers damage non-stick coatings. To protect the life of your non-stick pans, it's best to hand wash them using a mild detergent and a soft sponge.

COPPER COOKWARE—obvious to copper cookware owners, I bet. Running them through the dishwasher results in the items losing their coating when exposed to the machine’s hot water temperatures.

ANYTHING MADE OF WOOD. Cutting boards, spoons, salad bowls, and other kitchen items made from wood should always be hand washed. Anything made of wood will discolor and may even warp if washed in the dishwasher.

CRYSTAL. Abrasive detergents and the high water pressure don’t do it any good. We just gotta wrap our minds around the fact that crystal must be hand washed, and leave it at that.

ALUMINUM (cookware, serving items, etc.). For cookware and baking sheets, we’re talking pressed and cast cooking and bakeware. Like cast iron, the detergent, high heat, and minerals in your water will trigger a reaction that darkens the metal, and also leave an unappetizing coating on it. Additionally, the jostling of items against each other can scratch surfaces.

But note: Cookware made out of ANODIZED aluminum can go in the dishwasher, because these items are protected from chemicals that are used during the wash cycle.

Here I was, thinking I knew all about this stuff, and that most of you did too. But I learned some things (and maybe you did, too?) and want to thank Madeline for sharing her research. Going forward, some of my dishwashing habits and routines are definitely going to change!