When it comes to making life easier in the kitchen, nothing beats the convenience of a dishwasher. However, not all items are dishwasher-safe, and some can even be ruined or cause issues with your machine. So let’s dig into our top 10 things you shouldn’t put in the dishwasher.
Things You Shouldn’t Put in the Dishwasher: An Essential Guide
Here are some things you shouldn’t put in the dishwasher, along with tips to prevent or fix any potential problems.
1. Cast Iron Cookware
Cast iron is known for its excellent heat retention, making it perfect for cooking. However, it should never go in the dishwasher. Wondering why you shouldn’t put pans in the dishwasher? Dishwashing detergents can strip away the nonstick seasoning you’ve worked so hard to build up, leaving the pan vulnerable to rust. Instead, clean your cast iron cookware with plain water and a nonabrasive sponge, and dry it thoroughly to prevent rusting.

2. Sharp and High-Quality Knives
Putting sharp knives in the dishwasher can dull the blades, and it can also be a safety hazard when loading and unloading the machine. The high temperature and rough tumbling could also damage the handle of these knives, particularly those with hollow handles. Maintain your knives’ sharpness and longevity by washing them by hand with warm, soapy water.
3. Crystal and Hand-Blown Glass
These delicate items can easily chip or crack in the dishwasher. Moreover, crystal can become cloudy and pitted over time due to repeated exposure to high heat and strong detergents. Preserve the beauty of your crystal glasses and hand-blown glass pieces by washing them by hand and not banging around noisily in the dishwasher.
4. Wood Items
Wooden cutting boards and utensils can warp or crack under the intense heat of the dishwasher. Additionally, prolonged exposure to moisture can lead to the growth of bacteria. To keep your wooden kitchen items in good condition, wash them by hand and dry them immediately.
5. Non-Dishwasher Safe Plastics
Not all plastics are created equal. Some can warp or melt in the high heat of a dishwasher, while others might release harmful chemicals. Always check for the dishwasher safe symbol on plastic items, and when in doubt, hand wash.
6. Pressure Cooker Lids
Pressure cooker lids, including those for Instant Pots, contain various valves and seals that can be compromised by dishwasher detergents or clogged by small food particles. Always hand wash these components and make sure they’re dried thoroughly before storing them.
7. Insulated Mugs
Insulated mugs and containers, such as travel mugs or some water bottles, should not be put in the dishwasher. The heat can damage the vacuum seal, rendering the insulation useless.

8. Antiques, Heirlooms, and Hand-painted Ceramics
Priceless antiques, cherished family heirlooms, and hand-painted ceramics are items that you shouldn’t put in the dishwasher. The heat, water pressure, and detergents can damage these delicate pieces, potentially causing loss of value or sentimental heartbreak. Treat these items with the care they deserve by hand washing them.
9. Items with Paper Labels
Paper labels can loosen and remove in the dishwasher, creating a messy clean-up job as pieces of paper can clog the dishwasher drain or stick on other dishes. If you need to clean a jar or container with a paper label, remove the label first.
10. Copper, Pewter, and Aluminum
These materials can tarnish or darken when exposed to heat and detergents in a dishwasher. To keep these items looking their best, it’s advisable to hand wash them.
Keeping your dishes clean doesn’t have to mean risking damage to your valued kitchen items. By being mindful of things you shouldn’t put in the dishwasher, you can ensure your kitchenware stays in good shape for years to come. If you’re wondering what you can put in the dishwasher, we have another blog on that topic!
Should you experience any issues with your dishwasher or have any concerns, don’t hesitate to contact Moore Appliance for professional dishwasher service. Our expert team is always ready to assist you with all your appliance needs.