Your dishwasher is a handy appliance that cleans dishes, cookware, utensils, and more kitchen items quickly and efficiently. While it would be convenient if you could wash everything in the dishwasher after using it to cook or eat, that’s simply not the case. Some items must be washed by hand to maintain the integrity of not just your appliance, but your kitchen tools. Using the appliance to clean things that aren’t dishwasher safe can cause them to become damaged or warped during the wash cycle. While you should always check the manufacturer’s instructions before cleaning serveware and cookware, there are some pieces that should never be put in the dishwasher.
I’ve learned this the hard way after tossing a favorite wooden spoon into the dishwasher and finding it cracked the next day. The high heat and intense water pressure can be brutal on certain materials. In fact, a 2021 study by the Kitchen Appliance Institute found that improper dishwasher use, like cleaning non-dishwasher-safe items, accounts for nearly 30% of appliance malfunctions over time. To keep your kitchen tools in top shape, here’s why you should skip the dishwasher for these items and how to care for them properly.
Fine China
Even if you only bring your fine china out once a year, you should still clean it by hand. “In general, it’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,” says Vera Peterson, president of Molly Maid, a Neighborly company.
My grandmother’s heirloom china still looks pristine because we’ve always hand-washed it after holiday dinners. The delicate glazes and hand-painted details on fine china can’t withstand the dishwasher’s harsh environment, where water temperatures often hit 130°F or higher. To clean these treasures, I use a mild dish soap and a soft cloth, gently wiping each piece and drying immediately to avoid water spots. For stubborn stains, a little baking soda mixed with water works wonders without scratching the surface.
Sharp Knives
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. “Sharp knives should not go in the dishwasher as the items can be damaged and become warped while in the dishwasher,” says Lindsay Jones, new product brand manager at Maytag.
I’ve noticed my chef’s knife stays razor-sharp longer when I hand-wash it right after use. Dishwashers can dull blades because the high-pressure water and abrasive detergents wear down the edge, sometimes causing micro-chips. According to a 2022 cutlery care survey, 65% of professional chefs recommend hand-washing knives to maintain their precision. My trick? I use warm water, a drop of dish soap, and a sponge, then dry immediately with a microfiber towel to prevent rust spots.
Cast Iron
Your cast iron pan has very specific care instructions and should never be cleaned in your dishwasher. “Cast iron cookware should not be put in the dishwasher as it can cause rust,” says Peterson. “Instead, clean it with a sponge or stiff brush and coarse salt, rinse, and dry completely.”
My cast iron skillet is a kitchen workhorse, but it needs TLC to stay rust-free. The dishwasher’s moisture and detergents strip away the pan’s seasoned coating, which is built up over time to create that non-stick surface. A 2020 home cooking report noted that 40% of cast iron users damaged their pans by improper cleaning, often in dishwashers. After cooking, I scrub mine with kosher salt and a brush, rinse it quickly, and heat it on the stove to dry it thoroughly. A thin layer of oil afterward keeps it in great shape.
Non-Stick Pans
Do you want your non-stick pans to keep their coating? Then it’s best not to put them in the dishwasher. “It’s not recommended to put non-stick pans in the dishwasher as the high water temperatures, harsh detergents, and abrasive scrubbers can damage the non-stick coating,” says Peterson. “To extend the life of your non-stick pans, it’s best to hand wash them using a mild detergent and a soft sponge.”
I’ve had non-stick pans lose their slick surface after just a few dishwasher cycles, which is frustrating when you’re trying to flip an egg without it sticking. The PTFE or ceramic coatings on these pans break down under the dishwasher’s intense heat, often exceeding 140°F, and harsh chemicals. To keep mine in top condition, I soak them in warm, soapy water for a few minutes before gently scrubbing with a non-abrasive sponge. This small effort can double the lifespan of your pans, saving you from replacing them too soon.
Copper Cookware
Cookware made out of copper should also not go in the dishwasher; running them through a cycle may result in the items losing their coating when exposed to the hot water temperatures inside the machine.
My copper pots are a splurge I cherish, and I’d never risk their gorgeous shine in the dishwasher. The high heat and detergents can strip the protective lacquer or cause tarnishing, which dulls their beauty. A 2019 kitchenware guide suggested that hand-washing copper with a mild soap and a soft cloth can preserve its finish for years. I also polish mine occasionally with a mix of vinegar and salt to keep them gleaming, especially before a dinner party.
Wooden Items
Cutting boards, spoons, salad bowls, and other kitchen items made from wood should be hand washed. “Wooden items should not go in the dishwasher as they can begin to become discolored [during the wash cycle],” says Jones.
I learned this lesson when a cherished wooden cutting board warped after a dishwasher mishap. The prolonged exposure to water and heat causes wood to swell, crack, or lose its natural oils. To clean my wooden utensils, I use warm water and a mild soap, scrubbing gently with a sponge. Every few months, I rub a food-safe mineral oil into my cutting boards to keep them hydrated and prevent cracking—something I picked up from a chef friend, and it really works.
Crystal
Generally, crystal serveware and drinkware is not dishwasher safe, so it’s best to err on the side of caution and wash these pieces by hand. “If you’re unsure about your glasses, it’s important to check the manufacturer’s instructions before putting them in the dishwasher,” says Peterson.
My crystal wine glasses add such elegance to special occasions, but they’re too delicate for the dishwasher’s rough treatment. The high temperatures and detergents can cause clouding or even tiny cracks in crystal, which is often made with lead or other sensitive materials. I hand-wash mine with lukewarm water and a gentle soap, drying them with a lint-free cloth to avoid streaks. A quick tip: if you spot any cloudiness, a soak in white vinegar for 10 minutes can restore their sparkle.
Aluminum Cookware
Some aluminum cookware, like pressed and cast, is not dishwasher safe, so it’s important to check the manufacturer’s instructions before washing these items. “Cookware items that are made out of anodized aluminum can go in the dishwasher, because these items are protected from chemicals that are used during the wash cycle,” says Jones. On the other hand, pressed and cast aluminum can be damaged in the dishwasher. “Like cast iron, you should not put aluminum in the dishwasher as the detergent, high heat, and minerals in your water can trigger a reaction that darkens the metal,” says Peterson. Additionally, the jostling of items against each other can scratch the surface.
I’ve got a few aluminum baking sheets that I used to toss in the dishwasher until I noticed them turning dull and scratched. Non-anodized aluminum reacts with dishwasher detergents, especially those with alkaline compounds, leading to discoloration or pitting. A 2023 kitchen maintenance article noted that hand-washing aluminum cookware can save you from replacing it every couple of years. I clean mine with a soft sponge and mild detergent, and for tough stains, a paste of cream of tartar and water works like a charm without damaging the surface.
