Dishwasher safe means an item will survive the cycle. It does not mean the cycle is good for it, and the two are frequently confused.

Glass Etches Over Time

Repeated dishwasher cycles produce a permanent cloudiness in glass that is not residue and cannot be removed.

It is surface etching, caused by the combination of alkaline detergent, heat and soft water. Excess detergent and very soft water accelerate it considerably.

Using less detergent and a rinse aid helps. Handwashing anything you care about avoids it entirely.

Plastic Lids Are the Vulnerable Part

  • The heating element sits at the bottom of most machines
  • Plastic near it distorts, even when the water temperature is fine
  • A warped rim no longer presents a flat surface to seal against
  • Light lids flip in the spray, fill with water and come out dirty
  • Which is why guidance specifies the top rack

Where a manufacturer states top-rack dishwasher safe rather than dishwasher safe generally, of the kind at hom-berking.com, that is a real distinction rather than caution.

Secure the Lids

Wedged between rack tines, or in a rack designed for them.

A lid that has flipped over during the cycle needs rewashing rather than putting away, and it has probably knocked something.

The Gasket Channel Is Never Reached

The important limitation. A dishwasher cleans by water striking a surface, and the groove beneath a silicone gasket is enclosed.

No number of cycles cleans it. It has to be peeled out and washed by hand every few months, or the residue that accumulates there becomes the smell in your containers.

They Come Out Wet

Not a fault. Dishwashers dry by heating items so residual water evaporates from the hot surface.

Glass holds heat and dries itself. Plastic has low thermal mass and cools immediately, so water sits on it.

Opening the door at the end of the cycle and letting items air dry resolves it.

Do Not Wash Glass and Light Plastic Loose Together

A plastic item that shifts can chip a glass one, and chipped glass should be retired.

Staining Is Not Dirt

Where plastic components have stained from tomato or turmeric, no cycle removes it. It is cosmetic.

Dry Before Storing

Anything put away damp, particularly sealed, grows mould in the gasket.

Handwashing Extends Everything

A fair trade for items used daily.