Wash these things by hand:
- Cast iron, even enameled cast iron
- I let these pans cool, then add water if there is residue from grilling or pan-frying. Let stand until the residue is softened, then use a stiff brush to brush the softened remains right down the drain. Use a little soap as needed, but water is almost always sufficient. I dry the pan with a cloth, and finish on the stove over very low heat. Re-season as needed, or just wipe with a little neutral oil.
- Wooden or bamboo tools: these can warp or crack
- Good knives: You’ve just spent a small fortune on a really good knife. Wash it by hand. In the dishwasher, it gets banged around and you can even lose chips from the edge.
- Non-stick pots and pans. The only ones worth having are the Swiss diamond finish in my opinion, and even though it’s diamond hard, the finish can scratch. Teflon just weakens and flakes off, eventually into your food.
- Good crystal, china, and anything gold-rimmed. Even your dishwasher manual tells you not to put anything “good” into the dishwasher.
- Silpats will wrinkle and lose their shape.
- Aluminum pans are too light and will fly around during the cycles, leaving black marks on anything they hit.
- Copper: the dishwasher soap is too harsh for copper