A dishwasher is a beautiful thing, so handy and convenient, so wonderful for preventing a pile of moldy dishes when life loses all inertia, but there are certain things that should never enter that cave of convenience if you want them to live to serve another day.
Crystal and hand-blown glass are sensitive to heat so they run the risk of cracking in the dishwasher; but that’s not the only risk. Detergents can chip at them, causing them to lose their shine.
Good knives should never be put in the dishwasher — they’re more fragile than you might think. The agitation of the dishwasher’s cycle turns the blade dull; and it can get dings and scratches from hitting other objects.
Bottles and cans
If you want to rinse cans and beans to recycle or reuse, it’s best to wash them by hand. Labels attached with glue can loosen and clog the spray arms or pump and affect dishwasher performance.
Full story at Huffington Post.