**8 Things You Absolutely Should Not Put in a Dishwasher **(And Why)
Maya ChenIf you’re anything like me, you love the convenience of a dishwasher. It’s a modern marvel that can save you time and effort. But here’s the kicker: not everything is dishwasher-friendly.
Putting the wrong items in your machine doesn’t just risk damaging them—it can ruin your appliance, leave sticky residues, or shorten the lifespan of your favorite kitchen tools.
This article isn’t about fear-mongering. It’s about clarity. It’s about giving you honest, practical advice so you can protect your belongings and keep your dishwasher running efficiently for years to come.
Let’s explore what science and experts say about dishwasher safety—and how to wash these delicate items properly.
📋 Dishwasher Safety: Quick Reference Guide
Item | Dishwasher Safe? | Why Not? | Best Cleaning Method |
|---|---|---|---|
Sharp Knives | ❌ No | Dulls blades; damages handles | Hand wash with mild soap; dry immediately |
Wooden Utensils | ❌ No | Warps, cracks, loses finish | Hand wash; oil occasionally |
Crystal/Fine China | ❌ No | Chips, clouds, etches | Hand wash gently; air dry |
Cast Iron | ❌ No | Strips seasoning; causes rust | Hand wash; re-season regularly |
Nonstick Cookware | ⚠️ Check Label | Damages coating over time | Hand wash with soft sponge |
Adhesive Labels | ❌ No | Leaves sticky residue; clogs filters | Remove labels before washing |
Insulated Mugs | ⚠️ Check Label | Compromises vacuum seal | Hand wash lid and body separately |
Copper Cookware | ❌ No | Tarnishes; discolors | Hand wash with copper cleaner |
Heirloom/Old China | ❌ No | Fades patterns; chips easily | Hand wash with care |
💡 Key Insight: When in doubt, check the manufacturer’s label. If it says "Hand Wash Only," trust it. The heat and pressure of a dishwasher are far more aggressive than gentle hand washing.
🔪 1. Sharp Knives and Wooden Utensils
Let’s start with a bit of a shocker. Recently, I saw Ina Garten post a picture on her Instagram, and guess what? She had knives in her dishwasher! Now, you might be thinking, “What’s the big deal?”
The real issue here is that most experts recommend not using the dishwasher for sharp knives and wooden utensils.