**8 things you should never put in the dishwasher** (and why)

 If you’re like me, you love the convenience of a dishwasher. It’s a modern marvel that saves you time and energy after a long day. But there’s a catch: not everything is dishwasher safe. If you put the wrong things in the machine, you not only risk ruining your favorite items, but you can also damage the appliance, leave behind sticky residue, and drastically shorten the life of your kitchenware. This isn’t scaremongering, it’s common sense. By understanding what scientists and culinary experts say about

safety, you can protect your investment and ensure your machine continues to perform efficiently for years to come. Let’s take a look at what not to put in your dishwasher and how to properly care for these delicate items.

The golden rule: when in doubt, check the manufacturer’s label. If it says “Hand wash only,” believe it. The intense heat and high water pressure of a dishwasher are much more aggressive than careful hand washing.

1. Sharp Knives and Wooden Utensils
Let’s start with something surprising. I recently saw a photo of chef Ina Garten on Instagram, and guess what? Her knives were in the dishwasher! You might be thinking, “What’s so special about that?”

In reality, the high water pressure forces knives against other items in the basket, causing the blade to dull incredibly quickly. Additionally, the intense heat and harsh detergents can cause wooden handles to crack, warp, or peel away from the blade. Finally, reaching blindly into a dishwasher full of hidden, sharp knives is a real safety risk.

How to maintain them: Wash knives and wooden utensils by hand in warm, soapy water immediately after use. Dry them immediately with a towel to prevent rusting (especially carbon steel), and store them safely in a knife holder or magnetic holder. Occasionally rub wooden handles with food-grade mineral oil to maintain the finish. Even if a knife is labeled “dishwasher safe,” hand washing will ensure it stays razor-sharp much longer.

2. Refined crystal and fine porcelain

2. Refined Crystal and Fine Porcelain
If you have beautiful crystal glass or fine porcelain, it deserves the royal treatment.
High-pressure water jets can cause fragile glass to collide with other dishes or shatter. Harsh detergents and intense heat can permanently damage the crystal’s surface, making it appear cloudy no matter how often you polish it. Additionally, delicate gold or silver plating is likely to fade, chip, or wash off completely.

Ceramics& Pottery

How to care for them: Line a plastic container with a towel to prevent slipping, and gently wash the pieces with a mild detergent and lukewarm water. Rinse them thoroughly and let them dry on a rack or dry them gently with a lint-free cloth. Never stack heavy objects on top of delicate pieces.

3. Cast Iron Pans
Cast iron pans are the undisputed workhorses of the kitchen, but they can’t stand the  dishwasher. Harsh detergents and high temperatures remove the polymerized layer of oil—also known as “seasoning”—that gives cast iron its natural nonstick properties. Without this protective layer, the iron will quickly rust when exposed to moisture and air. Repeated use in the dishwasher will severely damage the iron’s surface over time.

Care Instructions: Hand wash with hot water and a stiff brush (soap is rarely needed). Dry pan completely on stovetop over low heat and lightly oil after each wash to maintain nonstick coating. Never soak cast iron pans for extended periods.

4. Non-stick pans
It may seem counterintuitive, considering that non-stick pans are designed to be easy to clean, but they are not dishwasher safe.

Dishwashers

Harsh detergents and high temperatures will damage non-stick coatings (such as PTFE or Teflon), causing them to chip and lose effectiveness. This will accelerate wear and tear, meaning you’ll need to replace your expensive pans much sooner. How to care for them: Hand wash with a soft sponge and mild detergent. Avoid abrasive pads such as steel wool. Always let your pan cool completely before washing to prevent warping. Although some newer ceramic-coated pans are labeled dishwasher safe, hand washing will always extend their lifespan.

5. Anything with adhesive labels
We’ve all tried to scrub a sticky sticker off a  plate after a dishwasher cycle—it’s a nightmare.
The heat and water will cause the labels to break down, leaving a tough, sticky residue on your dishes and inside your machine. Worse, the paper shreds and melted glue can clog your dishwasher’s filter, drastically reducing its cleaning efficiency. You’ll spend more time removing the residue than you’ll save by using the machine.

How to maintain them: Always remove all labels and stickers before placing them in the printer. Soak stubborn labels in warm, soapy water to loosen the adhesive, and carefully use a razor blade or scraper to remove any remaining adhesive residue.

6. Insulated travel mugs and thermoses
Insulated mugs are fantastic for keeping drinks at the perfect temperature, but the dishwasher can damage the interior.

Dishwashers

High heat can damage the vacuum seal between the double walls, making the mug less effective at retaining temperature. Additionally, plastic lids and rubber seals can warp or wear out, leading to leaks, and harsh cleaning agents can leave a lingering chemical taste or odor in the cup.

Care: Hand wash the bottle and lid in warm, soapy water, and use a bottle brush to thoroughly clean the inside. Let the bottle dry completely without the lid to prevent mold. Always follow the manufacturer’s instructions, but hand washing is usually the safest option. 7. Copperware

Copper pots and pans are beautiful kitchen treasures, but they are incredibly sensitive to use.

Harsh detergents and high temperatures quickly damage the beautiful finish, causing darkening and staining. A dishwasher cannot provide the special care needed to maintain the shine, and some detergents can even chemically react with copper, causing corrosion or tarnishing.

Care: Hand wash with mild soap and warm water, then dry immediately to avoid water spots. Polish regularly with copper cleaner or a simple homemade lemon juice and salt paste.

8. Antique or valuable porcelain
If you have old, hand-painted porcelain dinnerware or  bowls

Bowls